Bidding is a live auction where multiple ad networks are called at the same time to respond to a publisher’s ad request, and all have equal opportunity to compete. By letting multiple demand sources bid on the same inventory simultaneously, your eCPM yield might increase, which can lead to higher overall revenue. In the end, the ad network with the highest eCPM wins the bid request.
Unity Mediation supports the following ad networks as bidders:
If you are using a hybrid model to optimize your revenue by implementing both bidding and a traditional waterfall, the winning header bid then goes on to compete with your waterfall line items. In this hybrid model, the winning bid is combined with the eCPM target line items and sorted in descending order by comparing the bid price of the bidding line items with the eCPM targets of the traditional waterfall line items. The highest eCPM value between all the traditional waterfall line items and the winning bid is the ultimate winner in a hybrid model.
Bidding works differently than traditional line items. Waterfalls require you to create ranked eCPM targets so ad networks can individually be called to meet an ad request sequentially, but bidding requires no eCPM target setting nor ranked ordering of line items. If you are using third-party ad networks as a bidder, then you need to create placements and line items for each bidder.
For more information about this type of mediation strategy, view this video on bidding.