Reference / Glossary / Infrastructure and standards
Supply-Side Platform
Also: SSP; Sell-side platform
Software publishers use to sell inventory programmatically: connecting to exchanges and DSPs, running auctions, setting floors, managing deals, and reporting yield. Major SSPs include Google Ad Manager (which is also the dominant ad server), Magnite, PubMatic, Index Exchange, OpenX, and Freewheel. The line between SSP and Ad Exchange has largely dissolved.
Used in The Signal
Cite this entry:
Agency Echelon. "Supply-Side Platform." Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/glossary/supply-side-platform/