In a very long interview with Scott King the best selling author talks about doing creator owned material:
Scott: …I know you write comics but do you have any desire to do a creator owned comic book?
Brad: You know, if time was not an issue I would. But when I do the comics I love playing with those established toys. I love playing with Superman and Batman, but as much as I love that there is nothing like your own toy. Even though a creator owned book can be like that the novels are the houses I get to build brick by brick with my hands and I like that. My novels are my creator owned books. So I feel like when I play with comics I’m going to go play with the established toys and when I do the novels I’m going to build a house. But if time weren’t an issue I probably would do creator owned comics and that’s something I may try to figure out in the future.