CPM
In practice, for a UK buyer
The paragraph above is the neutral answer. This is the part a vendor glossary leaves out.
Two cautions. A CPM in a plan is a forecast, not a rate, because most inventory is auctioned per impression. And a blended CPM computed by averaging two days of averages is a fabricated number — AdBuyMCP's delivery payload refuses to produce one, keeping ratios and cost averages as dated observations that are never summed. Data segments add their own CPM uplift on top of the media: roughly £2.50 per thousand for Bombora topics and £3.00 for Dun & Bradstreet segments, shown on the plan rather than absorbed.
Goes deeper: The fee, and everywhere else the money goes
What this one connects to
Most confusion in media buying comes from two adjacent terms being used interchangeably, so these are the neighbours worth reading next.
CPC
The cost of one click on an advert, and the standard price unit for paid search and for much of paid social, where the advertiser pays for a response rather than for the impression that produced it.
CPA
The cost of one completed action, whether that is a sale, a lead or a booking, calculated by dividing spend by the actions attributed to it. That makes it entirely dependent on the attribution model underneath.
Working media
The portion of an advertising budget that actually buys advertising, as opposed to the portion consumed by platform fees, data costs, agency fees, ad serving and production. Usually expressed as a percentage of total spend.
Real-time bidding (RTB)
The auction mechanism underneath most programmatic advertising: when an impression becomes available, buyers are invited to bid on it and the winner's advert is served, all within roughly a hundred milliseconds.
More on buying and commercials
How media is transacted and where the money goes. The terms in this group are the ones a fee conversation turns on.
45 minutes. Bring a real brief and we compile it live. You describe one audience and watch it compile into seven targeting specifications, each with the score for how much of the definition survived.
Talk it through