An interface so that the world knows how they can distribute or re-use your writings.
Do you want people to redistribute your stories, articles, and web writing widely, as long as they give you credit?
Do you mind if people copy your stuff, so long as they don't make money off it?
Do you like the idea of other people making new works based on yours — provided they offer those derivations back to the public on the same terms?
Do you want to help create and have access to a pool of royalty-free writing?