What Is an SSP?
A Supply-Side Platform connects your app's ad inventory to advertiser demand, running auctions to find the highest-paying ad for each impression.
Top SSPs for Mobile in 2026
- Google AdX (via GAM): Largest demand pool, best Tier 1 eCPMs
- AppLovin MAX: Advanced in-app bidding mediation, 20+ network adapters
- Unity LevelPlay: Gaming expertise, strong rewarded video
- Meta Audience Network: High eCPMs from Facebook/Instagram advertisers
- InMobi: Strong APAC presence
- Pangle: TikTok advertiser demand
How In-App Header Bidding Works
All SSPs bid simultaneously on each impression. Highest bid wins regardless of waterfall position. Typically 10-30% eCPM uplift over sequential waterfalls.
OpenRTB Protocol
The IAB standard defining bid request/response format between SSPs and DSPs. Current version 2.6 includes rewarded video signals and supply chain validation.
How to Evaluate SSPs
Check fill rate, eCPM by geography, SDK size, format support, and bidding capability. RevenueFlex integrates the optimal SSP mix for each publisher's audience.