Performance marketing, defined in plain English.

ACoS is Amazon's primary PPC metric: ad spend divided by sales attributed to that spend, expressed as a percentage. Lower is better.

AOV is the average revenue per order. Increasing AOV is one of three core levers for ecommerce growth (alongside traffic and conversion rate).

Blended ROAS is total revenue divided by total ad spend across all channels. It's equivalent to MER, the honest top-down ad efficiency metric.

Brand safety is the discipline of preventing ads from appearing alongside harmful, controversial or off-brand content.

CAC is the total cost of acquiring one new paying customer, including ads, salaries and tooling. It's broader than CPA.

CPA is the cost to drive one conversion event: a purchase, signup, lead or install. It's the universal performance metric.

CPC is the average price paid per ad click. It signals creative resonance and audience demand, not conversion outcomes.

CPI is the cost to acquire one mobile app install. It's the dominant KPI for mobile UA campaigns on Meta, TikTok, and AppLovin.

CPL is the cost to acquire one lead, typically a form submission, demo request, or email signup. The dominant B2B and SaaS performance metric.

CPM is the cost to serve 1,000 impressions of your ad. It signals audience competitiveness and seasonal demand.

CRO is the practice of improving the percentage of visitors who complete a desired action (purchase, signup, lead form) through testing and optimization.

CTR is the percentage of impressions that result in clicks. It signals creative resonance and ad quality.

CVR is the percentage of clicks (or impressions) that complete a conversion event: purchase, signup, or install.

Frequency is the average number of times a single user has been exposed to your ad over a given window.

Hook rate is the percentage of impressions that watch past the first 3 seconds. It's the cleanest measure of a video ad's opening attention.

LTV is the total revenue or profit a single customer generates over their entire relationship with the business.

MER is total revenue divided by total ad spend. It's a blended, top-down profitability metric that's harder to game than platform ROAS.

Reach is the number of unique users who saw your ad at least once during the campaign window.

ROAS measures revenue generated for every dollar of ad spend. A 4× ROAS means $4 in revenue for each $1 spent.

ROI is profit (revenue minus cost) divided by cost. Unlike ROAS, ROI accounts for COGS, fulfillment and overhead.

TACoS is total Amazon ad spend divided by total Amazon sales (organic + paid). It measures ad efficiency across all sales, organic included.

Thumb-stop rate is the percentage of impressions that pause to engage. It's sometimes used interchangeably with hook rate, sometimes as the 1-second version.

Viewability is the percentage of impressions that meet IAB standards for being seen: at least 50% of pixels in view for at least 1 second (display) or 2 seconds (video).

VTR is the percentage of viewers who watch a video ad to completion (or to a target percentage like 75% or 100%).

Advantage+ is Meta's AI-driven campaign suite (Shopping, App and Sales) that automates audience, placement and budget decisions.

Connected TV is internet-delivered television (Roku, Apple TV, smart TVs, Hulu, Netflix Ads), increasingly bought programmatically.

DCO automatically combines creative elements (headlines, images, CTAs) at impression time to serve the best-performing combination per user.

Demand Gen is Google's mid-funnel campaign type for YouTube Shorts, Discover and Gmail. It replaced Discovery campaigns in 2024.

DPA serves automatically-generated ads pulling product data from a catalog feed, personalized to each user's likely interest.

A DSP is a platform that lets advertisers buy programmatic ad inventory across multiple ad exchanges from a single interface. It's the buy side of programmatic.

Performance Max is Google Ads' AI-driven campaign type that serves across Search, Display, YouTube, Discover and Gmail from a single asset group.

A product feed is a structured data file (CSV or XML) listing your product catalog (title, description, price, image, link) that powers DPA and Shopping ads.

Programmatic advertising is the automated buying of ad inventory through real-time auctions, replacing direct media buys with software.

A custom audience is a list of known users (emails, phone numbers, pixel events, or video viewers) used for retargeting or seeding lookalikes.

A frequency cap limits how often a single user sees your ad over a time window, preventing audience burnout and creative fatigue.

A lookalike audience targets new users who resemble an existing source list, typically your customers or your high-LTV cohort.

Retargeting serves ads to users who have already interacted with your brand: visited the site, watched a video, or added to cart.

ATT is Apple's iOS opt-in framework: apps must ask permission before tracking users across other apps and websites.

Attribution determines which ad touchpoint receives credit for a conversion, using last-click, first-click, time-decay or data-driven models.

CAPI sends conversion events directly from your server to the ad platform, bypassing browser-side limitations of pixel tracking.

A conversion event is a tracked user action that signals a goal completion: purchase, signup, install, lead form submit. The unit of attribution.

Cookie deprecation is the phasing out of third-party cookies in browsers, breaking traditional cross-site tracking and attribution.

DDA is Google's ML-based attribution model that distributes credit across touchpoints based on observed conversion paths in your account.

First-party data is information you collect directly from your customers: purchases, signups, behavior on your site. Privacy-safe and durable.

GA4 is Google's event-based analytics platform that replaced Universal Analytics in July 2023. Cross-platform, privacy-friendlier, harder to use.

A geo-experiment uses geographic regions as test/control groups, running ads in some markets and pausing in others to measure incremental lift.

A holdout test withholds ads from a randomly-selected control group, then compares performance vs. the test group to measure incremental lift.

Incrementality measures the additional revenue ads generate vs. what would have happened without them, usually measured via holdout tests or geo-experiments.

Last-click attribution credits the final ad click before conversion with 100% of credit. The default model on most ad platforms; systematically over-credits bottom-funnel.

MMM is a top-down statistical method that estimates each marketing channel's contribution to revenue using time-series data. It's privacy-friendly and attribution-window-agnostic.

An MMP is a third-party tool (AppsFlyer, Adjust, Singular, Branch) that handles mobile app attribution across ad networks, including SKAN and probabilistic modeling.

A pixel is a JavaScript snippet on your website that sends user behavior events (pageview, add-to-cart, purchase) back to ad platforms.

SKAdNetwork is Apple's privacy-preserving framework for mobile attribution. It provides aggregated, delayed conversion data without exposing user IDs.

UTMs are URL parameters (utm_source, utm_medium, utm_campaign) that tag traffic so analytics tools can identify where users came from.

A view-through conversion is credited when a user sees an ad without clicking it, then converts within the attribution window.

An A/B test compares two versions of an ad (or any variable) head-to-head against the same audience to identify the better performer.

A+ Content is Amazon's enhanced product description module, with multimedia layouts with images, comparison charts and brand storytelling on listing pages.

ASO is the practice of improving an app's visibility and conversion rate in the App Store and Google Play through metadata, screenshots, and keywords.

A brand kit is a defined set of brand assets (logo, color palette, fonts, voice) enforced consistently across all generated creative.

Carousel is a multi-card ad format on Meta, LinkedIn and Pinterest: 2-10 swipeable cards, each with its own image, headline and link.

Creative fatigue is performance decay caused by users seeing the same ad too many times, measured by rising CPM and frequency.

The hook is the first 1-3 seconds of an ad: the moment that earns attention and decides whether the rest of the ad gets watched.

A multivariate test simultaneously tests multiple variables (e.g. 5 hooks × 3 images × 2 CTAs = 30 combinations) to find the best combination.

Reels is Meta's short-form video format on Instagram and Facebook: 9:16 vertical, hook-driven, 6-90 seconds.

Shorts is YouTube's vertical short-form video format: 9:16, up to 60 seconds, monetizable as ads via Demand Gen and Performance Max.

Spark Ads on TikTok promote organic creator posts as paid ads, preserving the creator's handle and engagement signals.

A static ad is a non-video ad creative: an image, graphic or composite. Still the dominant format on Meta Feed and Pinterest despite Reels' rise.

Stories is Meta's full-screen 9:16 vertical ad format on Instagram and Facebook. 24-hour duration, immersive, swipe-up interaction.

UGC is creator-style content (testimonials, unboxings, demos) used as ad creative. Originally human-produced; now also AI-generated.

ABO sets budgets at the ad set level rather than the campaign level. Used for testing where each ad set needs guaranteed spend to produce signal.

A bid cap sets the maximum amount you'll pay per impression or click. Older Meta bid strategy that exposes more control than cost cap or target CPA.

CBO sets a single budget at the campaign level; Meta auto-distributes across ad sets based on real-time performance.

Cost cap is a Meta bid strategy that limits maximum CPA. The platform spends as much as possible while keeping CPA at or below the cap.

A daily budget caps how much a campaign or ad set can spend per calendar day. The most common budget-setting structure on Meta, TikTok and Google.

Smart Bidding is Google's family of automated, ML-driven bid strategies: Target CPA, Target ROAS, Maximize Conversions, Maximize Conversion Value.

Target CPA is a Smart Bidding strategy that aims to maximize conversions while keeping average cost per acquisition at your specified target.

Target ROAS is a Smart Bidding strategy on Google (and Meta's equivalent on Advantage+) that sets bids to hit a specified return on ad spend.

BOFU is the conversion stage: high-intent audiences ready to purchase, served retargeting and DPA ads.

MOFU is the consideration stage: users who have engaged with your brand but haven't yet purchased.

TOFU is the awareness stage of the marketing funnel: cold prospecting to people who don't yet know your brand.