AdMob: Upgraded Version of AdMob Ad Unit ID Troubleshooting

Question

I've recently just upgraded to the new version of AdMob (the previous version is referred to as Legacy AdMob).

I imported my information from the Legacy AdMob to the upgraded version. I'm now unsure of how to add a new ad unit.

I have two (2) ads. One is a main screen ad (ad 1) and the other is on a different screen (ad 2). Ad 1 was created under Legacy AdMob. It has a Legacy Publisher ID and a Legacy Mediation ID under it. I recently created ad 2. It ONLY specifies an 'Ad unit ID'.

Of course, the Developer's resources from Google have not yet been updated (https://developers.google.com/mobile-ads-sdk/docs/admob/fundamentals?hl=en_US#xml).

My questions are: 1. Do I continue using the Legacy AdMob PUBLISHER ID for ad 1? 2. For Ad 2 do I use my NEW Publisher ID (I noticed AdMob gave me a new publisher ID when switched over from Legacy)?

Basically, now that I'm using the upgraded version of AdMob (switched over from Legacy AdMob; old AdMob), which ID* do I use to ensure I receive my income?

*The new IDs under the new/upgraded AdMob are also much longer and begin with things like:

ca-app-pub-[AD_UNIT_ID_NUMBER_HERE]

pub-[PUBLISHER_ID_HERE]

Do I include the prefix as noticed above?

Answer 1

The new AdMob ad unit IDs do begin with ca-app-pub. You should start using those. Include the entire ad unit in your app, such as ca-app-pub-1234567890123456/1234567890.

As for your traffic on existing versions of your app that use the old IDs, that's fine - there's a mapping between the old publisher/mediation IDs and the new ad unit ID (though it's not necessarily a 1-1 mapping). The new placements can be both a site ID and mediation ID merged into one, since in the new AdMob, an ad unit represents a mediation placement regardless of whether you're just using AdMob or whether you're mediating.

Hopefully that answers more questions than it raises.