What is SSP (Supply-Side Platform)?

An SSP (supply-side platform) is software publishers use to sell their ad inventory automatically at the best possible price. It exposes the publisher’s available impressions to multiple ad exchanges and DSPs simultaneously, runs the auction, and returns the winning ad — the seller-side counterpart to a DSP.

For streaming publishers, SSPs manage which advertisers can appear in their content, set price floors, and protect the viewing experience with rules like frequency capping and category blocking.

Advertisers rarely interact with SSPs directly, but supply-path quality matters: premium SSP relationships determine whether your ad runs on brand-safe, professionally produced streaming apps or low-quality inventory.