What is an SSP (Supply-Side Platform)?
An SSP is software publishers use to sell and manage their ad inventory across exchanges and demand sources.
Understanding SSPs
SSPs package inventory, set floors, manage deals, and send bid requests to exchanges and DSPs. They help publishers maximize yield by choosing the best demand for each impression. Deal types range from open auctions to private marketplaces and programmatic guaranteed. Floors, bundles, and brand‑safety settings shape who can buy and at what price. Reporting and analytics close the loop so publishers adjust strategy.
From the advertiser perspective, SSPs influence which inventory is available and how it's described. Supply paths can be curated to improve quality and transparency. As formats expand (CTV, audio), SSPs translate publisher requirements into standardized bid requests. Latency and viewability controls protect user experience. The SSP sits alongside the DSP and exchange in the programmatic stack.
Why SSPs matter
SSPs matter because they determine which inventory reaches advertisers and under what conditions. Private marketplaces and curated deals help ensure brand safety and inventory quality. Understanding SSP dynamics helps advertisers negotiate better access and evaluate supply path optimization opportunities.
- Access: Advertisers reach inventory via SSP connections.
- Quality: Private marketplaces and deals help ensure brand safety.
- Transparency: Supply path data reveals intermediaries and costs.
How SSPs work
SSPs work by connecting publisher ad servers to exchanges and demand sources, packaging each impression with metadata like size, placement, and context. When a user loads a page/app, the SSP creates a bid request and forwards it to exchanges and DSPs. It applies floors and deal rules to control pricing and eligibility. The exchange runs an auction, returns a winner, and the SSP serves the creative via the publisher’s stack. Reporting flows back so publishers adjust floors and deals to improve yield and quality.
