I have a game on the play store made with construct2 and cocoonjs.
It's also here on scirra arcade and on my website burps-games.com if u wanna check it out(Barff Brain-Training).
With CocoonJS you can include ads from mopub/admob. There is a plugin for cunstruct2 too. With that plugin you can set visibility and position of the ads through events. (e.g. "On Start of layout show adbanner on bottom center")
The results exported with cocoonjs are really nice, but you have to fix audio and screen issues/bugs.
Appmobi seems to have more options like analytics, ads, push-notifications available to c2. Just look at the appmobi-c2-plugin. I never got that far, because I haven't been able to export an app with appmobi which had clear graphics. Looked always horrible.
Worst thing with cocoonjs is not to be able to trigger device buttons on android devices. If the "back"-key is pressed the app is closing immediately. Thats sucks, because users dont expect that. Would be nice to call a "Do you really want to quit?"-dialog or to go back to another layout instead.
But to your question, yes it is possible to bring games, made with c2, to the play store and to monetize it through ads.
Right now it's not just done with one click, but the guys from c2 are working pretty hard on it. There are huge improvments all the time.