Supply-Side Platform (SSP)
Technology used by publishers to manage, sell, and optimize their available advertising inventory across multiple ad exchanges and demand sources.
Definition
A supply-side platform is a technology platform that enables digital publishers to manage their advertising inventory and maximize revenue by connecting to multiple ad exchanges, demand-side platforms, and ad networks simultaneously. The SSP automates the process of making inventory available for programmatic purchase and uses algorithms to ensure publishers receive the highest possible price for each impression.
SSPs provide publishers with tools to set floor prices, control which advertisers can access their inventory, manage direct deals alongside programmatic sales, and analyze performance across all demand sources.
Why It Matters
Publishers need SSPs to compete effectively in the programmatic marketplace. Without one, publishers would need to manually manage relationships with each ad exchange and demand source, losing the ability to capture the best price for every impression in real time.
For marketers, understanding SSPs helps explain why the same inventory can appear at different prices across exchanges and why publisher-direct deals sometimes offer better placement quality than open exchange buying.
Examples in Practice
A news publisher uses an SSP to simultaneously offer their homepage ad slots across five different ad exchanges, with floor prices set higher for above-the-fold placements to protect premium inventory value.
A network of food blogs connects to an SSP that automatically identifies and blocks ads from competitor food brands, protecting their content partnerships while still maximizing programmatic revenue.
A mobile app developer uses an SSP with header bidding to let multiple demand sources compete for each in-app ad impression simultaneously, increasing their effective CPM by 25%.