Supply-side platform (SSP)
In practice, for a UK buyer
The paragraph above is the neutral answer. This is the part a vendor glossary leaves out.
The relevance to a buyer is the fee stack. A supply-side platform takes a fee and an exchange layer can take another on top of it, which is how the cumulative 'ad tech tax' arises without any single layer looking expensive. Knowing the SSP layer exists is what lets you ask the only question that matters about a media price: how much of this pound reaches the publisher?
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.
Demand-side platform (DSP)
Software an advertiser uses to buy advertising across many publishers through one interface, bidding on impressions in real time. It sits on the buyer's side of the market and charges a fee, usually a percentage of the media spent through it.
Ad exchange
A marketplace in which advertising impressions are auctioned between demand-side platforms buying and supply-side platforms selling. It matches bids to inventory in the milliseconds between a page or stream starting to load and the advert appearing.
Ad tech tax
The cumulative share of an advertiser's budget taken by the intermediaries between advertiser and publisher — demand platform, exchange, supply platform, data vendors, verification — none of which individually looks large.
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.
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