(supply-side platform/ sell-side platform)

A software platform which publishers can use to organize and offer their available ad space to ad exchanges (via RTB).

Supply-side platforms are used by online publishers to sell the banner impressions they can realise for advertisers within their portfolio at the highest price possible. SSPs are thus part of the programmatic buying process on the side of the publishers. On the side of the advertisers DSPs are used to buy these impressions at the lowest price possible. The DSPs and SSPs both provide an interface to help manage and organise the activities in the ad exchange.

Examples of SSPs are AppNexus and Google’s DoubleClick for Publishers.