Marketing Glossary
Clear, concise definitions for the marketing, analytics, and e-commerce terms you need to know. From ROAS to attribution models, find every term explained.
Analytics
7Conversion Rate
The percentage of visitors who complete a desired action, such as making a purchase, signing up for a newsletter, or requesting a demo. It is calculated by dividing the number of conversions by total visitors and multiplying by 100. Conversion rate applies to any measurable goal, including micro-conversions like adding items to a cart and macro-conversions like completing a purchase. Industry benchmarks vary widely: e-commerce sites average 2-3%, while SaaS landing pages often target 5-10%.
Bounce Rate
The percentage of visitors who leave a website after viewing only one page without taking any further action such as clicking a link, filling out a form, or making a purchase. A high bounce rate may indicate irrelevant content, slow page load times, or poor user experience. In Google Analytics 4, the equivalent metric is engagement rate, which measures the inverse: sessions where users actively interacted with the page. Bounce rate benchmarks depend on page type, with blog posts typically seeing 65-80% and product pages averaging 30-50%.
Cohort Analysis
A method of analyzing user behavior by grouping users who share a common characteristic, such as acquisition date, first purchase channel, or geographic region, during a specific time period. By tracking each cohort separately, marketers can identify trends in retention, revenue, and engagement over time rather than relying on aggregate metrics that obscure important changes. Cohort analysis is commonly visualized as a retention table where each row represents a cohort and columns show performance in subsequent periods.
Funnel Analysis
The process of mapping and measuring each step a user takes toward a conversion goal, from initial awareness to final action. It identifies where users drop off at each stage, enabling marketers to optimize the customer journey systematically. Common funnel stages include awareness, interest, consideration, intent, and purchase. Funnel analysis can be applied to any multi-step process, including e-commerce checkout flows, SaaS onboarding sequences, lead generation forms, and content engagement paths.
Customer Journey
The complete set of interactions a customer has with a brand, from initial awareness through consideration, purchase, and post-purchase loyalty. Customer journey mapping visualizes these touchpoints to reveal pain points, opportunities, and the overall experience from the buyer's perspective. The journey typically spans multiple channels including search, social media, email, website, and customer support. Modern journey mapping also accounts for non-linear paths where customers revisit earlier stages before converting.
A/B Testing
A controlled experiment comparing two or more versions of a webpage, email, ad, or other marketing asset to determine which performs better against a defined goal. Traffic is randomly split between variants, and statistical analysis determines whether observed differences are significant or due to chance. A/B testing is also called split testing. More advanced forms include multivariate testing, which evaluates multiple variables simultaneously, and multi-armed bandit testing, which dynamically allocates traffic to better-performing variants.
Brand Lift
A measurement of the positive impact an advertising campaign has on brand perception, awareness, or purchase intent. It is typically measured through surveys comparing exposed and control groups using tools like Google Brand Lift, Meta Brand Lift, or third-party solutions like Kantar and Dynata. Key metrics include aided and unaided awareness, ad recall, brand favorability, consideration, and purchase intent. Brand lift studies require statistically significant sample sizes, typically 5,000 or more respondents per group, and run for 2 to 4 weeks alongside the campaign.
Advertising
15ROAS
Return on Ad Spend measures the revenue generated for every dollar spent on advertising, calculated as total attributed revenue divided by total ad spend. A ROAS of 4:1 means four dollars in revenue for each dollar of ad spend. It is important to distinguish ROAS from ROI: ROAS only considers ad spend, while ROI factors in all costs including creative production, agency fees, and overhead. Industry benchmarks vary by channel, with Google Search averaging 2:1 to 8:1, Meta averaging 2:1 to 5:1, and display campaigns often falling below 2:1. A profitable ROAS threshold depends on your gross margin.
Return on Ad Spend
The full form of ROAS, it quantifies advertising efficiency by dividing total revenue attributed to ads by the total ad cost. The formula is: Return on Ad Spend = Revenue from Ads / Ad Spend. It is a key metric for evaluating campaign profitability and is reported as either a ratio (4:1) or a percentage (400%). Breakeven ROAS depends on your profit margin: a product with 50% gross margin needs a minimum 2:1 ROAS to break even on ad costs, while a 25% margin product requires 4:1. Industry benchmarks vary from 3:1 for e-commerce to 10:1 for software.
CPA
Cost Per Acquisition is the average cost to acquire one paying customer or conversion through advertising, calculated by dividing total ad spend by the number of conversions. Unlike CAC, which includes all business costs, CPA focuses specifically on advertising costs. CPA can be applied to any conversion event, from purchases to lead form submissions. Average CPAs vary dramatically by industry: e-commerce averages $45-$70, SaaS ranges from $50-$200, and financial services can exceed $300 per acquisition. Most ad platforms offer target CPA bidding, which uses machine learning to automatically set bids that achieve your desired acquisition cost.
CPC
Cost Per Click is the price an advertiser pays each time a user clicks on their ad. It is the dominant pricing model in search advertising and is also used in social and display campaigns. CPC is determined by an auction system where advertisers set maximum bids, but actual costs depend on competitor bids and quality factors. Average CPCs vary dramatically by industry: legal keywords can exceed $50 per click, while retail averages $1-$2. On Google Ads, actual CPC is typically 20-50% below the maximum bid due to the second-price auction mechanism.
CPM
Cost Per Mille (mille meaning one thousand in Latin) is the cost an advertiser pays for one thousand ad impressions. It is the standard pricing model for display, video, and programmatic advertising. CPM is calculated by dividing total ad spend by total impressions and multiplying by 1,000. Average CPMs range widely: social media display ads cost $5-$12, YouTube pre-roll averages $10-$30, and connected TV campaigns can reach $25-$50. CPM is most useful for comparing reach efficiency across channels and formats when the primary goal is brand awareness rather than direct response.
CTR
Click-Through Rate is the percentage of people who click on an ad or link after seeing it, calculated by dividing clicks by impressions and multiplying by 100. CTR benchmarks vary significantly by channel and placement: Google Search ads average 3-5%, display ads average 0.3-0.5%, Facebook feed ads average 0.9-1.5%, and email CTR averages 2-3%. CTR is influenced by ad copy, creative quality, audience targeting, and placement. A high CTR combined with a low conversion rate often indicates misleading ad messaging that attracts clicks but fails to deliver on the promise.
Impression Share
The percentage of total available impressions that your ads actually received in a given time period. Google Ads breaks this into two sub-metrics: impression share lost to budget (your budget ran out before all eligible auctions completed) and impression share lost to rank (your Ad Rank was too low to compete). Impression share is reported at the campaign, ad group, and keyword level. A 100% impression share means your ads appeared for every eligible search. For branded keywords, top advertisers typically target 90-95% impression share, while non-branded campaigns often operate at 40-70%.
Quality Score
A rating on a 1-10 scale used by Google Ads to measure the relevance and quality of your keywords, ads, and landing pages. It is composed of three components: expected click-through rate, ad relevance, and landing page experience, each rated above average, average, or below average. Quality Score is calculated at the keyword level and updated dynamically as performance data accumulates. While other platforms like Microsoft Ads use similar quality metrics, Google's Quality Score is the most widely referenced. A score of 7 or above is generally considered good, while scores below 5 indicate significant optimization opportunities.
Ad Relevance
A measure of how closely an ad matches the intent behind a user's search query or browsing context. Ad relevance is one of the three components of Google Ads Quality Score and is assessed by comparing the language and intent of your keywords to the messaging in your ad copy. Platforms evaluate relevance at the keyword-to-ad level, meaning a single ad group with tightly themed keywords will score higher than a broad group covering unrelated topics. Beyond search, ad relevance also applies to social and display campaigns where platforms score how well creative content matches the interests and behaviors of the targeted audience.
Retargeting
A digital advertising strategy that serves ads to users who have previously visited your website or interacted with your content, using browser cookies, pixels, or platform-specific identifiers to build audience lists. Retargeting can be site-based (targeting all visitors), page-based (targeting visitors of specific product pages), or action-based (targeting users who added to cart but did not purchase). Common retargeting platforms include Google Display Network, Meta, and programmatic DSPs. The typical retargeting window ranges from 7 to 90 days depending on the purchase cycle, with most conversions occurring within the first 7 days of the initial visit.
Lookalike Audience
An audience segment created by advertising platforms that mirrors the characteristics of your existing customers using machine learning algorithms that analyze hundreds of behavioral, demographic, and interest signals. The source audience (called a seed) can be based on customer lists, website visitors, or app users. Platforms like Meta offer percentage-based sizing from 1% (most similar) to 10% (broader reach), where smaller percentages yield higher match quality but smaller audience pools. Google offers Similar Audiences and Optimized Targeting, while LinkedIn provides Predictive Audiences with analogous functionality. The minimum seed size for effective lookalikes is typically 1,000-5,000 users.
Display Advertising
Visual ads including banners, images, rich media, and video shown on websites, apps, and social media through ad networks like the Google Display Network, which reaches over 90% of internet users worldwide. Display advertising encompasses standard IAB sizes (300x250, 728x90, 160x600), responsive display ads that automatically adjust to available placements, and native ad formats that blend with surrounding content. Display campaigns operate on CPM or CPC pricing models and are commonly used for brand awareness, retargeting, and product remarketing. The average display ad CTR across industries is approximately 0.35%, significantly lower than search ads but offset by much lower costs and broader reach.
Programmatic Advertising
The automated buying and selling of digital ad inventory using algorithms and real-time bidding (RTB), where each ad impression is auctioned individually in under 100 milliseconds. Programmatic advertising accounts for over 90% of all digital display ad spending and encompasses display, video, native, audio, connected TV, and digital out-of-home channels. The ecosystem includes demand-side platforms (DSPs) for buyers, supply-side platforms (SSPs) for publishers, and ad exchanges that facilitate the auction. Programmatic enables precise targeting using first-party data, third-party data, contextual signals, and machine learning-optimized bidding strategies.
DSP
A Demand-Side Platform is software that allows advertisers to buy digital ad inventory programmatically across multiple ad exchanges in real time. It provides centralized bidding, targeting, and campaign management across display, video, native, audio, connected TV, and digital out-of-home formats. DSPs use real-time bidding (RTB) to evaluate and bid on individual impressions in under 100 milliseconds. Major DSPs include The Trade Desk, Google DV360, Amazon DSP, and MediaMath, each offering different inventory access, audience data integrations, and optimization algorithms.
Paid Search
A form of digital advertising where businesses bid on keywords to display text, shopping, or local ads in search engine results pages. Also known as SEM (search engine marketing) or PPC (pay-per-click), it drives targeted traffic from users with high purchase intent. Google Ads dominates with approximately 90% market share, followed by Microsoft Ads at 6-8%. Paid search ads appear above and below organic results, with Google showing up to 4 ads at the top of the page. Ad formats include expanded text ads, responsive search ads, shopping ads with product images and prices, and local service ads with business ratings.
E-commerce
5ACOS
Advertising Cost of Sales is a metric used primarily on Amazon that measures ad spend as a percentage of attributed sales revenue. The formula is ACOS = Ad Spend / Ad-Attributed Revenue x 100. Lower ACOS indicates more efficient advertising spend. ACOS is the inverse of ROAS: a 20% ACOS equals a 5:1 ROAS. Amazon reports ACOS for Sponsored Products, Sponsored Brands, and Sponsored Display campaigns individually. Breakeven ACOS equals your pre-advertising profit margin, so if a product has a 30% margin, any ACOS below 30% generates profit while ACOS above 30% loses money on each ad-driven sale.
TACoS
Total Advertising Cost of Sales measures ad spend as a percentage of total sales revenue, including both organic and paid sales. The formula is TACoS = Total Ad Spend / Total Revenue (Organic + Paid) x 100. Unlike ACOS which only considers ad-attributed sales, TACoS provides a holistic view of advertising impact on overall business health. It captures the halo effect of advertising on organic rankings, since Amazon's A9 algorithm rewards sales velocity regardless of whether purchases came through ads or organic search. Healthy TACoS benchmarks range from 5-15% for established products and 15-25% during launches.