A Demand Side Platform (DSP) is an essential technology for automated trading of online advertising space. The platform is used in so-called programmatic advertising for the purchase of advertisements by submitting bids for them. These bids are then purchased via the ad networks and exchanges connected to the DSP. If I am the highest bidder, I win the advertising space and my ad is played out there. The whole thing works through real-time bidding, whereby the highest bidder is determined in real time. The big advantage of the DSP is that you can bid on many inventory sources at the same time. Normally, the DSP is also linked to data sources, so you can link your actions to meaningful targeting criteria.