I don't often read bestsellers. It's irrational, I know, but if a novel has mass-appeal, I automatically assume that it is, well, (and here's an adjective you don't hear anymore), lowbrow. I might read one if it has stood the test of time, like A. J. Cronin's The Keys of the Kingdom, or Maugham's Of Human Bondage.
(Reading this the next day, I feel I ought to add that on the "brow scale" I am probably a "middle". I don't often read Booker Prize winners either.)
I haven't yet read Steve Hely's How I Became A Famous Novelist, which I found in the donation bin, but on the back cover, noted as the author's "competition", is a very funny fake NYT Best Sellers list. You'll recognize the imaginary spinoffs for a number of genres: the endless fantasy saga, the Da Vinci clone, the "big name" licensed techno-thriller. The only genre conspicuously absent is the vampire novel.