Dan Brown is successful because reading "The DaVinci Code" feels a lot like watching the History Channel, which is to say that it feels very educational and high-brow, but ultimately probably isn't. Fortunately for DB, not many people are discerning enough to play the "Fact or Crap" game well; either that, or not many people care.

Also: his use of cliff-hangers at the end of most chapters provides a decent amount of momentum.

I think Dan Brown is a hack, though less odious of one than Stephanie Meyer, whom I read in hopes of knowing what my freshmen were talking about. Never again.