Case: +$2.70 RPM from adding 3 header-bidding partners

Case: +$2.70 RPM from adding 3 header-bidding partners

Header bidding = auctioning each slot to many exchanges in parallel before the ad server call. Tech blog, n=1, 28d.

Demand partners 4 → 7
Bid density (bids/auction) 3.1 → 5.4
Session RPM $16.10 ▮▮▮▮▮ → $18.80 ▮▮▮▮▮▮▮
Page latency +90ms (within budget)

More competing bids raised clearing CPMs on the same inventory. Diminishing returns appeared past partner 6.

So what: bid density drives clearing price; stop adding partners when latency outruns lift. ▲16.8%