Interesting... While I do hate ads (as a developer and as a consumer), I really like this approach...
https://pubnative.readme.io/v3.0/docs/games
Yeah, sometimes ads are really annoying in mobile games. But I find ads annoying mostly in two cases: bad done and ugly/unusefull ads.
Some developers that are starting to make games use to place too many ads in the game. Example: level->ad. level->ad. level->video ad -> UNINSTALL
Maybe we shouldn't put ads in the first minutes of play, or even in the first session: let the user play the game first!
Another point is the look of the ads. Have you seen
chartboost? It's an ad network for games. Those are really good looking ads, wich is important to get a good ctr ratio. For developers, the purpose of the ads isn't show as many as you can, it should be get the most installs you can, wich results in a high eCPM.
You can even make a custom frame for the ad, so it will look integrated in the game (in my opinion)
The problem with chartboost is that there isn't any sdk for b4a, only through mediation. Anyway, using additionaljar and with javaobject it should be easy to use any ad network. I've been doing some tests and I can allready show chartboost ads in my games. I'd like to test all functionalities of the sdk and I'll make a tutorial on how to do it, I think it's interesting.