This concept has its genesis in Europe. Basically it is a software for purchasing advertising in an automated fashion. DSPs are often used by the agencies and advertisers ( marketers ).These buy display, video, mobile and search ad inventory. DSPs facilitate the real-time bidding ( RTB ) access across multiple sources of inventory. DSPs provide access to more publishers. Previously the process of buying and selling digital ads was manual — there were human buyers and salespeople. They were costly and unreliable. DSPs make the process efficient by automation. It bypasses the need for negotiation of ad rates.

DSPs purchase ad impressions across a range of publisher sites. Still the ads are targeted based on certain attributes — location, previous browsing behaviour. DSPs try to find the best ROAS for an advertiser.