I own the business license as I have made over the $5000 with C2. I purchased it at one of the 50 percent off upgrade deals a while back.
To answer your how.
Ads on Google Play games
Sales on iOS games
Ads on Windows 8 games
Non exclusive license sales to publishers.
There are lots of ways to make money with HTML5 games :).
I've said it before. C2 makes it extremely easy to make games. However, there is a lot more that goes into making games that earn money than just the ability to make a game.