A
A/B Test
An A/B test is an experiment where you pit two variants of an ad, landing page, or other marketing element against each other to determine which performs better. Variant A is the control, variant B is the challenger. You split your traffic randomly and measure which variant achieves a higher conversion rate, CTR, or other KPI. Important: test only one variable at a time and wait for statistical significance before drawing conclusions.
Ad Frequency
Ad frequency indicates how often an individual user has seen your ad on average within a given period. A frequency of 3 means each person reached has seen your ad an average of three times. Too low a frequency means insufficient impact; too high a frequency leads to ad fatigue and declining performance. The optimal frequency varies by channel and campaign goal, but for awareness campaigns, 3–7 is a common guideline.
Ad Spend
Ad spend is the total amount you invest in paid advertising, excluding agency fees, tooling, and other overhead. It is the basis for calculating metrics like ROAS (revenue divided by ad spend) and CPA (ad spend divided by conversions). Manage your ad spend by setting clear budget limits per campaign and channel, and monitor daily whether your spending is in line with your targets.
Attribution
Attribution is the process of assigning conversions to the touchpoints that contributed to them. Which ad, which channel, or which interaction gets the “credit” for a conversion? Several attribution models exist: last click (the final click gets all credit), first click (the first one), linear (evenly distributed), time decay (more recent touchpoints get more), and data-driven (algorithmic). The model you choose determines which channels look better or worse — and therefore where your budget goes. Google Ads switched to data-driven as the default in 2023.
Average Order Value (AOV)
The average order value is the average amount per transaction: total revenue divided by the number of orders. AOV is a crucial metric for e-commerce performance marketing because it directly impacts your ROAS and profitability. A higher AOV means you can spend more per click and still remain profitable. Increase your AOV through upselling, cross-selling, free shipping above a minimum amount, or bundle offers.
B
Bid
A bid is the maximum amount you are willing to pay for a click, impression, or conversion in an ad auction. With manual bidding, you set this yourself; with Smart Bidding, the algorithm does it automatically based on your goals. The bid is one of the factors that determines whether and where your ad appears — but not the only one. Quality Score and relevance weigh at least as heavily.
Blended ROAS
Blended ROAS calculates your total revenue divided by your total ad spend, regardless of channel. While channel-specific ROAS is susceptible to double-counting due to attribution overlap (the same conversion is claimed by both Google and Meta), blended ROAS provides an honest view of your overall marketing effectiveness. It is closely related to MER. An e-commerce business with $100,000 in revenue and $20,000 in ad spend has a blended ROAS of 5. Monitor this metric on a weekly basis to spot trends.
Bounce Rate
The bounce rate is the percentage of visitors who leave your page without taking a second action — no scroll, no click, no form submission. In the context of performance marketing, a high bounce rate indicates a mismatch between your ad and landing page, slow load time, or an unclear call-to-action. Note: in GA4, bounce rate has been replaced by “engagement rate,” but the concept remains valuable. Aim for a bounce rate below 50% for Google Ads landing pages.
Brand Safety
Brand safety refers to measures taken to prevent your ads from appearing alongside unwanted, harmful, or controversial content. In programmatic advertising and display networks, you can use exclusion lists, content category filters, and third-party verification services. Brand safety is not a luxury but a necessity: a single screenshot of your ad next to extremist content can damage your reputation.
Budget Pacing
Budget pacing is the speed at which your budget is spent over a campaign period. “Standard” pacing distributes your budget evenly throughout the day or month; “accelerated” pacing spends as quickly as possible (and can exhaust your budget early in the day). Monitor your pacing daily — too slow means missed opportunities, too fast means you miss the best hours of the day.
C
CAC (Customer Acquisition Cost)
CAC is the total amount it costs to acquire one new customer, including all marketing and sales costs: ad spend, agency fees, salaries, tooling, and overhead. The formula: total acquisition costs divided by the number of new customers. CAC is broader than CPA, which only measures media costs. Always compare your CAC with your Lifetime Value: a healthy ratio is an LTV:CAC ratio of at least 3:1.
Campaign
A campaign is the organizational unit within which you group your ads, targeting, and budget. At the campaign level, you set the goal (awareness, traffic, conversions), budget, bid strategy, and audience. In Google Ads, a campaign contains ad groups; in Meta Ads, it contains ad sets. A clear campaign structure — segmented by goal, product, or funnel stage — is the foundation of every successful performance marketing account.
Clicks
Clicks is the number of times users click on your ad. It is the most basic interaction metric in performance marketing. Not all clicks are equal: a click on a search ad typically has higher purchase intent than a click on a display banner. Monitor not just the number of clicks, but also their quality — how long do clickers stay on your site, and how many convert? Lots of clicks without conversions points to a targeting or landing page problem.
Conversion
A conversion is a valuable action you define that a user takes after interacting with your ad: a purchase, lead form submission, phone call, app download, or sign-up. Solid conversion tracking is the foundation of performance marketing — without reliable data, you are optimizing blind. Define both macro-conversions (purchase, lead) and micro-conversions (newsletter sign-up, product page visit) to understand your full funnel.
Conversion Rate
The conversion rate is the percentage of users who convert after clicking on your ad: conversions divided by clicks, times 100. An average conversion rate for search campaigns is 3–5%, but this varies enormously by industry and conversion type. A low conversion rate with lots of clicks points to a landing page issue; a low conversion rate with few clicks may be a volume issue. Optimize through A/B testing, faster load times, and a clear call-to-action.
Conversion Window
The conversion window is the period after a click or interaction during which a conversion is still attributed to that ad. Google Ads uses a default click-through window of 30 days and a view-through window of 1 day. Meta Ads defaults to 7 days click and 1 day view. Your choice of conversion window affects how many conversions you measure: a longer window shows more conversions, but attribution becomes less precise. Align the window with your customer’s typical decision time.
CPA (Cost Per Acquisition)
CPA measures how much you pay per conversion: total cost divided by the number of conversions. It is the core metric for lead generation campaigns. A Google Ads campaign with $1,000 in spend and 20 leads has a CPA of $50. Note the difference from CAC: CPA measures only direct media costs, while CAC covers all acquisition costs. A declining CPA at consistent quality is every performance marketer’s goal.
CPC (Cost Per Click)
CPC is the amount you pay per click on your ad. The actual CPC is almost always lower than your maximum bid because ad platforms use an auction model. In Google Ads, your CPC is determined by the Ad Rank of the competitor below you, divided by your Quality Score. Average CPCs in the US range from $0.50 for niche keywords to $15+ in competitive verticals like finance and legal.
CPL (Cost Per Lead)
CPL is the specific variant of CPA for lead generation: your total cost divided by the number of leads generated. It is the primary KPI for B2B campaigns and service providers. A “lead” can be a form submission, quote request, or newsletter sign-up — clearly define what counts as a lead. Beyond CPL, also track your lead-to-customer rate: a CPL of $20 with a 10% conversion to customer is more effective than a CPL of $10 with a 2% conversion rate.
CPM (Cost Per Mille)
CPM is the cost per 1,000 impressions of your ad. It is the standard pricing metric for display, video, and social media campaigns. A CPM of $8 means 1,000 impressions cost you $8. CPM is relevant for awareness campaigns where reach is more important than direct clicks. Always compare your CPM in the context of your audience: a CPM of $25 for enterprise CEOs can be more valuable than a CPM of $3 for a broad audience.
Creative
A creative is the visual and/or textual element of your ad: an image, video, carousel, copy, or combination thereof. In performance marketing, creative testing is essential — you can have the best targeting and bid strategy, but with a weak creative, you will not get results. Systematically test different hooks, visual styles, and formats. Refresh your creatives regularly to prevent ad fatigue, especially in social media campaigns.
CTR (Click-Through Rate)
The CTR is the percentage of impressions that result in a click: clicks divided by impressions, times 100. An average CTR on Google Search is 3–5%; on Display and social media, 0.5–1.5% is common. Your CTR is a direct indicator of your ad’s relevance and appeal. In Google Ads, your CTR also influences your Quality Score, which in turn affects your CPC. A higher CTR thus indirectly leads to lower costs.
D
Daily Budget
The daily budget is the maximum amount you want to spend per day on a campaign. Google Ads can spend up to 2x your daily budget on busy days but compensates on slower days — over a month, you never pay more than 30.4 times your daily budget. Set your daily budget realistically: too low and your campaign learns too slowly, too high and you burn budget on traffic that does not convert.
Data-Driven Attribution
Data-driven attribution is an attribution model that uses machine learning to determine the actual contribution of each touchpoint to a conversion. Instead of giving all credit to the first or last click, the algorithm analyzes all paths that did and did not lead to conversions. Since 2023, this has been the default model in Google Ads. It requires a minimum volume of data to work reliably.
Demand Gen
Demand Gen is a campaign type in Google Ads (successor to Discovery campaigns) that shows ads on YouTube, Gmail, Discover, and the Display Network. It focuses on creating demand among potential customers who are not yet actively searching. Demand Gen combines visual-first creatives with Google’s targeting capabilities — ideal for filling the top of your funnel with qualified traffic.
Diminishing Returns
Diminishing returns is the phenomenon where each additional dollar you invest in a campaign yields less and less return. The first $1,000 might deliver 50 conversions (CPA $20), the next $1,000 only 25 (CPA $40). This is normal and unavoidable: you reach the most purchase-ready audience first, then progressively less interested users. Recognizing the tipping point is crucial for efficient budget allocation.
E
eCPM (Effective Cost Per Mille)
eCPM is the effective cost per 1,000 impressions, regardless of the pricing model. If you are paying on a CPC basis, you calculate the eCPM as: (total cost / total impressions) x 1,000. This makes it possible to fairly compare campaigns with different pricing models (CPC, CPM, CPA). A search campaign with a CPC of $1.50 and a CTR of 4% has an eCPM of $60.
Engagement Rate
The engagement rate measures the percentage of users who interact with your ad or content: likes, comments, shares, saves, clicks, or video views. In GA4, “engaged sessions” replaces the traditional bounce rate: a session counts as engaged if it lasts longer than 10 seconds, contains a conversion, or includes at least 2 page views. Engagement rate is a qualitative metric that indicates whether your content resonates with your audience.
F
First-Party Data
First-party data is all the data you collect directly from your own customers and website visitors: email addresses, purchase history, website behavior, CRM data, and customer lists. In a world without third-party cookies, first-party data is becoming increasingly valuable. Use it for remarketing lists, customer match audiences, and lookalike audiences. Businesses with strong first-party data have a significant competitive advantage in performance marketing.
Frequency Cap
A frequency cap limits the maximum number of times an individual user sees your ad within a given period. For example: a maximum of 3 impressions per person per week. Without a frequency cap, you can flood the same audience, leading to ad fatigue, negative brand associations, and wasted budget. Set frequency caps based on your campaign goal: awareness campaigns can have a higher cap than retargeting campaigns.
Full-Funnel Strategy
A full-funnel strategy combines campaigns for every stage of the customer journey: awareness (building visibility), consideration (evaluation), and conversion (purchase/lead). Instead of only investing in bottom-funnel search campaigns, you also invest in upper-funnel channels like YouTube and Display to reach your audience before they actively start searching. A healthy funnel distribution is typically 20% awareness, 30% consideration, 50% conversion.
G
Geo-Targeting
Geo-targeting is the practice of directing your ads at specific geographic locations: countries, regions, cities, zip codes, or even a radius around a point. In performance marketing, geo-targeting is essential for concentrating your budget where your customers are. Analyze your conversion data by region and adjust bids accordingly: increase for high-performing locations, decrease or exclude poor-performing ones. Note the difference between “people in this location” and “people who show interest in this location.”
H
Holdout Test
A holdout test is an experiment where you deliberately do not show ads to a portion of your audience (the holdout group) to measure the true impact of your campaign. By comparing the conversion rate of the group that does see ads with the holdout group, you determine the incremental value of your marketing. It is the gold standard for measuring true campaign effectiveness, especially with retargeting where many conversions would occur without advertising.
I
Impression
An impression is counted each time your ad is displayed to a user. A single user can generate multiple impressions. In search campaigns, an impression is a display in the search results; in display and social media, it is a display on a website, in a feed, or in a video. Note: an impression does not mean the user actually saw your ad — especially with display, the ad can be below the fold (outside the visible area of the page).
Impression Share
Impression share is the percentage of impressions you received out of the total number of impressions you were eligible for. An impression share of 60% means you are missing 40% of possible impressions. Google breaks down the loss into two causes: “lost due to budget” (insufficient budget) and “lost due to rank” (low Ad Rank). This helps you decide whether to allocate more budget or improve your Quality Score.
Incrementality
Incrementality measures the true, additional impact of your marketing. The core question: how many conversions would not have happened without this campaign? Not all conversions a platform reports are incremental — some would have occurred without advertising, especially with brand search and retargeting. Measure incrementality through holdout tests, geo experiments, or matched market tests. It is the most honest but also the most difficult to measure performance metric.
K
KPI (Key Performance Indicator)
A KPI is a measurable value that indicates how effectively you are achieving your objectives. In performance marketing, typical KPIs include: ROAS, CPA, CAC, conversion rate, CTR, and revenue. Choose a maximum of 3–5 KPIs per campaign and make sure they are directly tied to your business objectives. Avoid vanity metrics (impressions, clicks) as primary KPIs — they create a sense of success without actually generating value.
L
Landing Page
A landing page is the page a user arrives on after clicking your ad. Landing page quality is one of the most underrated factors in performance marketing: you can have the best ads and targeting, but if your landing page does not convert, you are burning budget. Essentials: fast load time (under 3 seconds), relevant content that matches the ad, a clear call-to-action, and social proof. In Google Ads, your landing page experience affects your Quality Score.
Lifetime Value (LTV / CLV)
Lifetime Value is the total revenue a customer is expected to generate over the entire customer relationship. A customer with a monthly subscription of $100 and an average retention of 24 months has an LTV of $2,400. LTV is crucial for determining your maximum acquisition costs: if your LTV is $2,400, you can accept a higher CAC than if your LTV is $200. The LTV:CAC ratio is the ultimate health metric for your business model.
Lookalike Audience
A lookalike audience is an audience that the ad platform creates based on similarities with your existing customers or website visitors. You upload a source list (customer match, pixel data) and the algorithm finds users with similar characteristics. In Meta Ads, you set a percentage (1–10%): 1% is the most similar but smallest, 10% is the broadest but less precise. Lookalikes are one of the most powerful targeting methods for scaling your campaigns.
M
Match Type
A match type determines how broadly or narrowly your keyword needs to match a user’s search query. Google Ads has three types: broad match (broad, including synonyms and related queries), phrase match (the meaning of your keyword must be present), and exact match (the search intent must match exactly). Broad match provides the most reach but requires strong negative keywords and Smart Bidding; exact match offers the most control but the least volume.
Maximize Conversions
Maximize Conversions is an automated bidding strategy in Google Ads that uses your budget to achieve the maximum number of conversions. The algorithm adjusts bids in real-time based on signals like device, location, time of day, and search behavior. It is effective when you have sufficient conversion data (at least 15–30 conversions per month) and your primary goal is maximizing volume, not efficiency. Optionally combine with a target CPA for more control.
Media Mix
The media mix is how you distribute your marketing budget across different channels: Google Ads, Meta Ads, LinkedIn, programmatic, affiliate, email, and more. The optimal media mix depends on your audience, product, funnel stage, and objectives. Use media mix modeling or incrementality measurements to determine which channels contribute most. Diversification protects you from dependence on a single platform.
Media Mix Modeling (MMM)
Media Mix Modeling is a statistical method that quantifies the impact of each marketing channel on your revenue, including offline channels. MMM uses historical data, econometric models, and controls for external factors (seasonal effects, economy, weather). It is less granular than digital attribution but provides a holistic view. Tools like Google Meridian and Meta Robyn are making MMM more accessible to mid-size businesses.
MER (Marketing Efficiency Ratio)
The MER is your total revenue divided by your total marketing spend. It is functionally identical to blended ROAS, but some marketers use it to emphasize that it includes all marketing costs, not just ad spend. An MER of 4 means every dollar of marketing generates $4 in revenue. MER is the most honest efficiency metric because it is immune to attribution problems and double-counting between channels.
Micro-Conversion
A micro-conversion is a smaller action that indicates a user is moving toward your ultimate goal: viewing a product page, adding an item to the cart, watching a video, or downloading a whitepaper. Micro-conversions help your algorithms learn faster (more data points) and provide insight into where users drop off in your funnel. Track them as secondary conversions, not as primary KPIs.
N
Negative Keywords
Negative keywords are keywords for which your ad must not appear. They prevent your budget from being spent on irrelevant traffic. Add negative keywords at the campaign or account level for broad exclusions (“free,” “jobs,” “internship”) and at the ad group level for specific exclusions. Regularly analyze your search terms report to identify new negatives — this is one of the most impactful optimizations you can make.
O
Optimization
Optimization is the continuous improvement of your campaign performance based on data and insights. This includes bid strategy adjustments, keyword management, ad copy testing, audience refinement, landing page improvement, and budget allocation. Effective optimization is iterative: analyze, hypothesize, test, measure, and repeat. The best performance marketers optimize not on instinct but on statistically significant data.
Optimization Score
The optimization score is a percentage (0–100%) in Google Ads that indicates how well your account is set up according to Google’s recommendations. It is based on suggestions like adding keywords, increasing budgets, or enabling extensions. Be critical: not all recommendations are in your best interest. Some suggestions increase Google’s revenue without improving your ROI. Evaluate each recommendation based on your own data and objectives.
P
Payback Period
The payback period is the time it takes for a customer to pay back the acquisition cost. If your CAC is $300 and a customer generates $100 per month with a margin of 50%, your payback period is 6 months ($300 / $50 net per month). A short payback period gives you more financial room to grow. SaaS companies aim for a payback period of 12 months or less; e-commerce businesses ideally want this within the first transaction.
Performance Marketing
Performance marketing is a discipline within digital marketing where you pay based on measurable results: clicks, leads, sales, or other concrete actions. Unlike traditional marketing (where you pay for reach), performance marketing is fully data-driven and results-oriented. The core principle: every dollar you invest must demonstrably contribute to your business objectives. Channels include Google Ads, Meta Ads, LinkedIn Ads, programmatic display, and affiliate marketing.
Performance Max (PMax)
Performance Max is Google’s most automated campaign type, combining all Google networks: Search, Display, YouTube, Gmail, Discover, and Maps. You provide assets (text, images, videos) and Google’s AI automatically optimizes where your ads are shown. PMax requires sufficient conversion data to work effectively and offers less transparency than traditional campaign types. It is particularly effective for e-commerce with product shopping, but requires close monitoring to prevent brand search traffic from being incorrectly claimed as PMax conversions.
Pixel (Tracking Pixel)
A pixel is a piece of code you place on your website to measure visitor behavior and track conversions. The Meta Pixel, Google Ads tag, and LinkedIn Insight Tag collect data on page visits, purchases, and other actions. This data is used for conversion tracking, remarketing lists, and lookalike audiences. With the shift toward server-side tracking and the end of third-party cookies, the pixel is being supplemented by tools like the Conversions API (CAPI).
Placement
A placement is the specific location where your ad is shown: a website, app, YouTube channel, or position in the search results. With display and video campaigns, you can manually select placements or let the platform choose automatically. Monitor your placement reports regularly and exclude poor-performing placements — mobile game apps and made-for-advertising websites are common budget wasters.
Programmatic Advertising
Programmatic advertising is the automated buying of ad space through real-time auctions (RTB). In milliseconds, the system determines which ad is shown to which user, based on data, bids, and targeting criteria. Programmatic offers scale and efficiency but requires expertise in brand safety, viewability, and fraud prevention. The supply chain is complex: DSPs (demand-side platforms), SSPs (supply-side platforms), and ad exchanges work together to trade impressions.
Q
Quality Score
The Quality Score is a rating from 1 to 10 that Google assigns to your keywords in Google Ads. It is based on three factors: expected click-through rate (CTR), ad relevance, and landing page experience. A higher Quality Score lowers your CPC and improves your ad position. A Quality Score of 7+ is good; below 5 requires immediate action. Improve by better aligning your ad copy to the keyword and making your landing page faster and more relevant.
R
Remarketing (Retargeting)
Remarketing is re-engaging users who have previously interacted with your website, app, or ads. You build lists based on specific behavior: visited a product page but did not buy, abandoned cart, read a blog post. Remarketing typically has a higher conversion rate and lower CPA than prospecting campaigns, but always measure the incremental value: some of these users would have returned without a reminder.
Responsive Search Ads (RSA)
Responsive Search Ads are the standard ad format in Google Search. You provide up to 15 headlines and 4 descriptions, and Google automatically combines them into the best-performing variations. Use all available headline slots, include keywords in at least half of the headlines, and ensure sufficient variety. Only pin headlines when absolutely necessary — it limits Google’s optimization capabilities.
ROAS (Return On Ad Spend)
ROAS measures how much revenue you earn per dollar of ad spend: revenue divided by ad spend. A ROAS of 5 means a $1 investment generates $5 in revenue. It is the most important KPI for e-commerce performance marketing. Note: ROAS does not account for product costs, margins, or overhead — a ROAS of 5 can be unprofitable at 15% margins. Always calculate your minimum ROAS based on your margins before setting targets.
ROI (Return On Investment)
ROI measures the actual return on your total investment: (revenue – all costs) divided by all costs, times 100%. Where ROAS only looks at ad spend, ROI accounts for all costs: products, salaries, agency fees, tooling, and overhead. A campaign with a ROAS of 4 can have a negative ROI if your margins are low. ROI is the metric that CFOs and executives care about most — it is the bridge between marketing and finance.
S
Scale (Scaling)
Scaling in performance marketing means increasing your campaign output (more conversions, more revenue) while keeping efficiency at an acceptable level. Scaling is not simply “adding more budget” — due to diminishing returns, your cost per conversion rises at higher budgets. Effective scaling requires opening new audiences, channels, geographies, or campaign types. Test, validate, and scale in phases. A common rule: increase budgets by a maximum of 20–30% per week.
Search Term
A search term is the actual text a user types into Google, as opposed to the keyword you target in your campaign. The search terms report shows which queries triggered your ads. Analyze this report weekly to discover valuable new keywords and add irrelevant queries as negative keywords. It is one of the most valuable optimization sources in Google Ads.
Server-Side Tracking
Server-side tracking moves data collection from the user’s browser to your own server. Instead of JavaScript pixels in the browser, conversion data is sent to your server and from there forwarded to ad platforms via APIs (such as Meta’s Conversions API or Google’s Enhanced Conversions). Server-side tracking is more reliable than client-side pixels, bypasses ad blockers, and is better prepared for the cookieless future.
Smart Bidding
Smart Bidding is the umbrella term for Google’s automated bidding strategies that use machine learning to optimize bids in real-time. Smart Bidding strategies include: Target CPA, Target ROAS, Maximize Conversions, and Maximize Conversion Value. The algorithm weighs hundreds of signals: device, location, time of day, browser, search behavior, and more. Smart Bidding requires sufficient conversion data and reliable tracking to work effectively.
Spend Efficiency
Spend efficiency measures how effectively you are spending your marketing budget. It is an overarching concept that combines metrics like ROAS, CPA, CAC, and MER. High spend efficiency means you are achieving maximum results with minimal waste. Improve your efficiency by excluding irrelevant traffic, shifting budgets to best-performing campaigns, testing creatives, and optimizing your landing pages.
T
Target CPA
Target CPA is a Smart Bidding strategy in Google Ads where you set a desired cost per conversion. The algorithm automatically adjusts bids to hit that goal on average. Set your target CPA realistically based on historical data — a target that is too low will drastically limit your volume, while one that is too high wastes budget. Start with your current average CPA and gradually reduce by 10–15% per adjustment.
Target ROAS
Target ROAS is a Smart Bidding strategy that optimizes for a desired Return On Ad Spend. You set a target percentage (e.g., 500% = $5 revenue per $1 ad spend) and the algorithm adjusts bids to achieve this goal. Target ROAS works best for e-commerce with dynamic product values and requires accurate conversion value tracking. A minimum of 50 conversions in the past 30 days is recommended.
Tracking (Conversion Tracking)
Tracking is the systematic measurement of user actions on your website after interacting with your ads. Reliable tracking is the absolute foundation of performance marketing: without accurate data, you cannot optimize, report, or scale. Implement server-side tracking alongside client-side pixels, use UTM parameters for campaign source identification, and audit your tracking monthly for accuracy. Common issues: double-counting, missing conversions, and incorrect attribution.
U
UTM Parameters
UTM parameters are tags you add to URLs to identify the source, medium, and campaign of your traffic in Google Analytics. The five standard UTMs are: utm_source (source, e.g., “google”), utm_medium (channel, e.g., “cpc”), utm_campaign (campaign name), utm_term (keyword), and utm_content (ad variant). Consistent UTM tagging is essential for reliable reporting. Use a UTM naming convention and document it — inconsistent naming makes your data unusable.
V
Viewability
Viewability measures whether an ad was actually visible to the user. The IAB standard: a display ad is “viewable” if at least 50% of its pixels were visible for at least 1 second; for video, this is 50% for at least 2 seconds. On average, 60–70% of display impressions are viewable — meaning you are paying for 30–40% of impressions that nobody sees. Monitor viewability in your reports and exclude placements with low viewability.
View-Through Conversion
A view-through conversion is a conversion that occurs after a user sees your ad but does not click on it. For example: someone sees your display ad, later searches directly for your brand, and makes a purchase. View-through conversions are valuable indicators of the impact of your awareness campaigns, but do not add them on top of your click-through conversions — that leads to double-counting. Use them as supplementary insight, not as a primary KPI.
W
Walled Garden
A walled garden is a closed advertising ecosystem in which a platform has full control over data, targeting, and measurement. Google, Meta, and Amazon are the three largest walled gardens. You can use data within the platform but cannot export it or combine it with data from other platforms. This makes cross-channel attribution difficult and is one of the reasons why blended ROAS and media mix modeling are becoming increasingly important.
Wasted Spend
Wasted spend is the portion of your ad budget spent on clicks or impressions that generate no value: irrelevant search terms, non-converting placements, wrong audiences, or underperforming creatives. On average, 20–30% of Google Ads budgets are wasted. Reduce waste by regularly analyzing your search terms report, adding negative keywords, pausing underperforming campaigns, and tightening your targeting. This is often the fastest way to improve your ROAS.