There's something called the 'Washington Read,' which is the habit of many locals to go into a bookstore, pull a book off the shelf, rifle through the index to see if they're in there.
If I see Marian Keyes' books or Patricia Scanlan's books given more prominence than mine in the bookstore, I'll move mine to the front. I've told them I do this, and they've confessed to doing the same thing to me.
My books are often shelved around those of Chinua Achebe and Margaret Atwood, or Chimamanda Adichie and Monica Ali. All of this depends, of course, on the bookstore and how conversant the shelf stocker is with the alphabet.
I picked up 'On Moral Fiction' in the bookstore and looked up myself in the index, but I didn't read it through. I try not to read things that depress me.
A lot of the ways of advertising a book - the cover, whether somebody sees it on a subway or sees it in a bookstore - those things are going to rapidly diminish as we move to an electronic model.