How does integrating one network into another work? I created an acccount on mopub, and made an ad unit. I didn't integrate the Mopub SDK into my app, instead I just copied the Mopub ad unit ID, and added Mopub as a mediation on Admob, with that ad unit ID. Did I go about it the right way? Because on Mopub's dashboard it shows 0 impressions.
Everything you have done is correct, but you still need to include the Mopub library in your app because the Admob mediator will invoke the Mopub classes when Mopub has been selected in the mediation flow.