Paid media glossary: advertising terms, defined

In short

A working glossary of paid media: the efficiency metrics (ROAS, CPA, CPM, ACoS), the measurement concepts that decide whether those metrics can be trusted (attribution windows, incrementality, blended ROAS), and the campaign and creative terms that come up in every account review.

Metrics

ROAS — Return on ad spendROAS (return on ad spend) is the revenue generated by advertising divided by the amount spent on it. A campaign that spe...Break-even ROASBreak-even ROAS is the return on ad spend at which a campaign covers its costs exactly, calculated as 1 divided by gross...CPA — Cost per acquisitionCPA (cost per acquisition) is ad spend divided by the number of conversions. Spending $2,000 to generate 50 conversions ...CPC — Cost per clickCPC (cost per click) is ad spend divided by clicks. It measures what you pay for attention, not for results. CPC is set ...CPM — Cost per milleCPM (cost per mille) is the cost of one thousand impressions, calculated as ad spend divided by impressions, multiplied ...CTR — Click-through rateCTR (click-through rate) is clicks divided by impressions, expressed as a percentage. An ad shown 10,000 times and click...Conversion rate — CVRConversion rate (CVR) is conversions divided by clicks or sessions, expressed as a percentage. If 1,600 clicks produce 5...AOV — Average order valueAOV (average order value) is total revenue divided by number of orders. $48,000 across 600 orders is an AOV of $80. AOV ...ACoS — Advertising cost of saleACoS (advertising cost of sale) is ad spend divided by attributed sales, expressed as a percentage. It is the standard e...TACoS — Total advertising cost of saleTACoS (total advertising cost of sale) is ad spend divided by total revenue including organic sales, expressed as a perc...FrequencyFrequency is the average number of times each person saw your ad, calculated as impressions divided by reach. A frequenc...ImpressionsAn impression is one instance of your ad being served. Impressions count deliveries, not people: the same person seeing ...ReachReach is the number of unique people who saw your ad at least once, as distinct from impressions, which count every deli...

Targeting

Retargeting — RemarketingRetargeting is advertising to people who have already interacted with your business, such as site visitors, video viewer...Lookalike audienceA lookalike audience is an audience the platform builds by finding users who resemble a source list you provide, such as...Negative keywordsNegative keywords are terms you exclude so your ads do not show for them. They are the main tool for stopping wasted spe...

Campaign types

Advantage+ — Advantage PlusAdvantage+ is Meta's automated campaign framework, where the platform handles audience selection, placement and creative...Performance Max — PMaxPerformance Max (PMax) is Google's automated campaign type that serves across Search, Shopping, YouTube, Display, Discov...Programmatic advertisingProgrammatic advertising is the automated buying and selling of ad inventory through real-time auctions, rather than by ...

Measurement

Blended ROAS — MERBlended ROAS is total revenue from all sources divided by total advertising spend across all platforms. It is sometimes ...Quality ScoreQuality Score is Google's 1 to 10 diagnostic of how relevant your keyword, ad and landing page are to a user's search. I...Attribution windowAn attribution window is the period after seeing or clicking an ad during which a conversion is still credited to that a...IncrementalityIncrementality is the share of conversions that genuinely happened because of advertising, rather than conversions that ...MCP — Model Context ProtocolMCP (Model Context Protocol) is an open standard for connecting AI assistants to external tools and data. An MCP server ...

Creative

Ad fatigue — Creative fatigueAd fatigue is the decline in performance that happens when an audience has seen the same creative too many times. The cl...Creative testingCreative testing is the practice of running multiple ad concepts against the same audience to find which message, format...Safe zoneA safe zone is the area of an ad creative that stays clear of interface elements such as profile names, captions, button...Rich media adsRich media ads are display ads that go beyond a static image, using video, audio, animation or interactive elements the ...

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