I thought about selling my ebook like this (I'm only making 33 cents per book as is, anyway) but then I couldn't figure out how to do it.

I usually toss Humble Bundle about $5 or $6. I'd like to pay more, but I'm broke. Sometimes I'll buy a couple extra bundles as gifts, though. The nice thing about Humble Bundle is all the publicity they get. A lot of these are indie games that no one would have ever heard of otherwise and through Humble Bundle they're able to get some publicity via word-of-mouth and a lot of people suddenly playing the games. I blog about Humble Bundle games I've bought and enjoyed greatly all the time.