I managed to get around £40 so far with my Bowls app. I released as a free version initially, when I updated it I created a LITE and paid version at Android minimum price. I have 80 downloads for the paid version since published on 6th March. My free version has almost 4000k downloads since last October. I did setup Admob / Mopub in my LITE version a months ago. That has only generated estimated £8 since then. I have not setup payments out for either yet and the Abmod you need to get alot higher amount before they pay anything out.
https://play.google.com/store/apps/deta ... ygames.smb
Not amazing success story but as a C2 is just a spare time hobby I am fairly happy with the results so far =P
I've not spend any money on advertising / promoting kind of thing. Just on a few bowls forums posting details of my free app. It comes up fairly high on the Google store listing now when on Sports games / New Paid Apps =)
Any thing I get from it I just see as some spending money =)