Demand side platform (DSP) is an automated buying platform where advertisers and agencies go to purchase digital ad inventory. Essentially, DSP ad servers are used to buy mobile ads, search ads, and video ads from a designated marketplace where publishers list their advertising inventory. These online advertising platforms allow you to manage advertising across real-time bidding networks. Together with supply-side platforms, DSP ad tech enables programmatic advertising — and can be integrated into multiple ad exchanges, as well.