The Humble Bundle is a charity focused deal. Each offering they put together a theme oriented group of games, comics, or books or programs or different things. At different donation levels you increase the size of the bundle. The top tier starts at $15 but you can donate more if you like. Right now it is e-cookbooks, "Eat like a geek". https://www.humblebundle.com/books/...eek_bookbundle&linkID=&utm_content=cta_button You usually get a choice of formats like epub, pdf, mobi. sometimes a particular book might have only one format but there are tools to convert between the formats. I already have the offered Chinese Street Food book. I've not cooked from it yet but it's been interesting and I like it.