A company such as Marvel, DC, Dark Horse or Tokyo Pop partners with a web print-on-demand service (like Lu Lu.com) and starts a new sub-company/website. This website is an Alternate Universe of the comic company’s core world and allows people to host their comics that feature the comic company’s characters.
Here’s a scenario:
Little Timmy in the 6th Grade does a 22-page Superman comic. He uploads it to the DC FanWorld website. The website automatically places a DC FanWorld logo in the upper-left corner of the cover. The website creates a preview of the book for everyone to see. Then he (and his friends at school and myself or whoever else) orders his 22-page comic off of the website for 4 or 5 dollars. This money is split between DC, the print-on-demand service, and the cartoonist.
Little Timmy’s comics become very popular and sells more than some of DC’s Direct-Market distributed comics. Timmy can create an alternate universe inside DC FanWorld that starts a completely new mythology of the characters, drawn by Timmy and his friends.
I don’t know how this couldn’t be profitable or worthwhile for the company and, personally, I’d love to see more of the fan-fiction in print and widely available.