Bidding enables ad sources to compete in a real-time auction to fill your ad requests and helps ensure you get the highest revenue for your impressions.
In this article:
What is bidding?
Bidding enables ad sources to compete in a real-time auction to fill your ad requests. This helps ensure that you’re getting the highest revenue for your impressions.
Unlike waterfall mediation, which relies on user-provided eCPM or historical data to prioritise networks and call them one at a time, bidding calls all participating ad sources simultaneously. The ad sources bid on each impression in real time. This allows them to compete equally in a single, unified auction.
For any given impression, the ad source that serves the ad is the highest paying advertiser.
How does bidding work?
Bidding works seamlessly with existing or new mediation groups. Each bidding ad source competes to fill ad requests along with the other ad sources, like waterfall ad sources, which do not participate in bidding.
1. An ad unit generates an ad request
An ad unit in your app generates an ad request and sends it to AdMob along with targeting information, such as platform and ad format.
2. AdMob matches the ad request to one of your mediation groups
AdMob Mediation compares the ad request to the targeting settings and priority of the mediation groups that you've defined. It matches the ad request to the mediation group with the correct targeting settings and, if there is more than one, the highest priority.
3. AdMob initiates a bidding auction
Once the ad request is matched to a mediation group, the bidding ad sources in the group compete in an auction to fill the request.
The ad source that submitted the highest eCPM bid will then be placed in the mediation waterfall according to the eCPM value.
4. Mediation waterfall functions as usual and the ad request is filled
If a bidding ad source is placed first in the mediation waterfall, it will get the opportunity to serve the ad. If the bidding ad source is not the highest eCPM in the mediation waterfall, the waterfall ad sources will be called first.
Currently, bidding ad sources do not support ad serving for child-directed apps or ad requests. Learn more about US COPPA.
Similarly, your bidding ad sources must be included as an ad technology provider. To select ad technology providers in AdMob, click Blocking controls in the sidebar and click the Manage EU user consent tab.
Example 1: Bidding mediation group
There are four bidding ad sources in the mediation group. Each source submits a bid for an available ad unit. In this example, there are no waterfall ad sources in this mediation group. This means that the highest bidding ad source serves the ad.
There are four bidding ad sources in the mediation group. Each source submits a bid for an available ad unit.
Network B wins the bidding auction with a £7 bid and is placed according to its eCPM value in the mediation waterfall. In this example, Network B’s bid is higher than other waterfall ad source bids. Therefore, Network B is placed first in the waterfall and gets to serve the ad. The waterfall ad sources are not even called.
In this example, Exchange B wins the bidding auction with a £4 bid and is placed according to its eCPM value in the mediation waterfall. However, Network 1 has a higher eCPM value (£5) than the winning bid from Exchange B. Therefore, Exchange B is placed second in the waterfall.
From now on, the waterfall functions normally. Network 1 serves the ad if it has one. If not, Exchange B will serve the ad.
Example 4: Bidding with direct sold in a mediation group
In this example, Exchange A wins the bidding auction with an £8 bid and is placed according to its eCPM value in the mediation waterfall. However, your direct sold campaign has a higher eCPM value than the winning bid from Exchange A. Therefore, Exchange A is placed second in the waterfall.
From now on, the waterfall functions normally. Your direct sold campaign serves the ad if there is one. If not, Exchange A will serve the ad.
Get started with bidding
There are two types of bidding ad sources that you can use in your mediation groups:
- Bidding ad sources that require additional setup before you can use them and must be added to a mediation group.
- Bidding ad sources that don’t require any setup and are included as part of the AdMob network.
Learn more about the types of bidding ad sources. Then, set up a bidding ad source and add it to an existing or new mediation group.
SDK implementation
To use bidding, ensure that you’ve integrated bidding mediation into your app. Also note that some ad sources may have additional SDK requirements.
Learn more about the ad sources available for bidding and their requirements in the Google Developers guide for Android and iOS.
How can I use bidding?
Bidding is covered by our App Platform Feature Policy. Before enabling bidding, review the AdMob behavioural policies.