OK, I know what you're thinking — maybe you're not a writer. However, as Tamez says above, chances are, you're an expert sy ~something~. Also, chances are that other people want to know what you know. So whether you write an eBook on dating or tips on how to fix your car, once you write, self-publish the book, and let it go, it can sit on a site like Amazon and sell itself. Of course, you can market it, too, but that's another story! Some sites let you keep most of the earnings, while others do not.
My goal with this site is really only to write about 25-30 pages with information as I learn about boats and do customizations to my boat. I’m also adding a forum. Forums seem to be very popular with boat owners so I’m anxious to have others generate content for me. I don’t have huge plans for this site, but I’m sure it will bring in a few thousand a month if I don’t fizzle out. This is going to be my fun project for the next little while.