Yeah, that just doesn't sound right. Perhaps he's also counting additional organic installs, which he attributes to the increase in rank he got from the paid installs?

This is how installs are sold, after all - 'yes, X per install sounds like a lot, but if you buy enough you'll top the leaderboard and get many many more, so you'll really only be paying X/10 per install...'

I should have explained this a little better in the article. The ads boosted the game enough to get us onto some of the lesser Android featured areas, so most of those installs were organic.

I just came here to ask the same thing. We've just started trying out Chartboost and their minimum is $0.50 per install

Might be relevant, but an old version was using leadbolt according to my data.