Auction per ad unit and lazy auction
Last edited: 2024/08/08
What is Auction per ad unit?
- When using Auction per ad unit (Auction per ad unit = <on>), the Prebid auction is triggered only on the ad units detected on the URL the user is currently browsing. This means we first send one big request for all ad units detected instantly. Then, when additional ad units appear (e.g., due to lazy loading), we send additional bid requests to Prebid.
- In the regular Prebid setup (Auction per ad unit = <off>), the Prebid auction is triggered on all ad units defined for a given domain or on ad units associated with the page (which requires using the pages feature in the Inventory tab). In this scenario, Prebid Stack will always send one “big” bid request for all ad units, regardless of whether they are lazy loaded or not shown at all on the given URL.
Benefits of using Auction per ad unit
- you limit the amount of unnecessary bid requests (the requests that have no chance of ending up with an impression which not only increases how SSPs perceive our inventory and improves their bidding but also reduces your carbon footprint
- the bid requests are smaller hence faster to process
How to use it?
In Prebid Stack > Domains > Edit > Edit domain configuration > toggle Auction per AdUnit <on>
Disabling Auction per ad unit
Sometimes you might want / need to disable this option. The potential reasons for that are:
- When you want to make your Prebid setup faster and improve the GAM’s ad speed metrics. Learn more in GAM documentation: link.
- When you are using Single Page Architecture
In such case, all ad units must have div ids defined in the Platform’s interface.
Lazy auctions
What is lazy auctions
If you are using lazy load (whether the lazy load from Prebid Stack or Google Publisher Tag’s), you can improve even more the auction per ad unit, calling ad units within a view port range. For example, if a user is visiting example.com/news, a page with 10 ad units but only 3 above the fold, the other 7 will initiate an auction within a defined distance from the view port, when the user scrolls down.
Benefits of the lazy auction
First, the lazy auction uses the auction per ad unit. So the same advantages apply (increased viewability, eCPM and page speed). These are just increased a step further (since you trigger the auction with the lazy load which aims to increase the ads viewability).
How to use lazy auctions
In Prebid Stack > Domains > Edit > Edit domain configuration: Lazyload
- Make sure to have the lazy load <ON>. For more information: lazy load.
- Toggle <ON> Enable lazy auctions
- Input the {Auction Margin Percent}: percentage of the view port. For example: a value of 100% will trigger the auction 1 view port from the ad unit. A value of 200, will trigger the auction 2 view ports from the ad unit.
