I do! I confess, one peep at a book cover tells me whether or not it's a book I want to try. I like 'illustrations' rather than photographic reality, pastel colours are a bonus, but sometimes vibrant bright colours act as a draw as well. Does that make me very shallow?
I used to. Boy, I'll never forget when I saw the cover to Dear Sir, I'm Yours by Joely Sue Burkhart, which probably evoked the most visceral positive response I've ever had to a book cover. I -had- to read that book immediately and it still remains one of my favorites. I highly recommend it if you are into reading about BDSM but want something outside of the usual club-oriented focus.
Unfortunately, ever since I had to switch over to e-books entirely due to aging eyes and an inability to wear glasses without getting a headache, I now pay very little attention to the covers any longer - it's the blurbs that determine whether I'll read a book or not. Not that I don't still pay attention to the covers once I get the book, but my first "point of contact" now is usually the blurb.