47th way

Write an ebook. It's as easy as falling off a chair. Know something about something? Whether it's about growing cabbages, writing PERL, plucking nose hair or being a good cop - if you're a good marketer, or pay a good marketer, you can probably sell a few thousand copies of your ebook. People pay online and download it, no publisher, printer, book shop or other cumbersome details to worry about. In fact, you don't even need to do the selling. "Affiliates" do it for you (on commission). And, there are ebooks telling you how you can write and sell ... ebooks!