For the past month I have been averaging around $2 per 1000 impressions. Using AdMob via MoPub.
Some days it went as low as 0.74, and others, as high as $4, it varies a lot.
I notice a pattern, one day high CPM, next day low, day after that high, then low. It kinda alternates. My theory is the Ads aren't "new enough" on the 2nd day, and if ppl already seen/click on it, they wouldn't do it again, until more "new Ads" are shown. I have nothing to base it on, just a hunch.
As for income, just recently released some games and now starting to earn enough to pay a few bills. Not too bad, hopefully it keeps on growing, and soon I'll have another good game out.