Kind of touched on this in another thread, but I figured I'd ask you guys as you're probably more knowledgable about this and I can give a more detailed post.
Why don't DC/Marvel release original full length novels set in their universes?
Not comics or long arcs, but full on novels with only words. Not adaptations of their movies or already done arcs like Final Crisis or Civil War. I'm talking about actual fully realized stories that are fleshed out by decent authors hired by Marvel or DC.
DC have released a few in the last few years, one based on Superman,
another based on Superman and Batman, and
most recently in 2012 with a story based around Thomas Wayne. I haven't checked out any of them but might try to check out the first two, along with a few Batman novels from earlier.
Marvel have not been so expansive. There were a string of Wolverine books in the mid 2000s, along with a few others based around Spider-Man, Fantastic 4, and Iron Man, among others. But those stopped in 2010 and since they have been releasing some major comic arts in novel adaptations, like Death of Captain America, Kraven's Last Hunt, and Astonishing X-Men. However, Dan Abnett did write a Groot and Rocket Raccoon "prose" novel that came out just last month, but it seems to be aimed more at children than adults.
Why not bring in a few authors to write one or two original novels a year? Completely original ideas or maybe based on cancelled story arcs that never saw the light of day. There has to be a decent sized market out there. Have they ever commented on anything like this?