There's an excellent essay by Richard Wheeler on Ed Gorman's blog today, about the differences between literary and popular fiction and how they came about. As someone who writes popular fiction, and pretty quickly, at that, I'm in agreement with Wheeler. Some years ago, I took part in a seminar at Texas Christian University about Western fiction, the theme of which was "But Is It Literature?" Several working Western writers were invited, and we made the argument that literature is where you find it. The academics disagreed and seemed to be more of the opinion that literature is where they say it is. They were reasonably polite about it, though.
Personally, I don't think I've ever claimed that what I write is literature. I try to turn out good, solid commercial fiction that my audience will enjoy reading. But that doesn't mean that I can't sneak in something every now and then that I think is worth saying.