[UPDATE] - On the NTY Book Review and Tolkien - More on this story. Patti got a response from an editor at the NYT Book Review. The long-story-short of it is that they don't put certain books on the bestseller lists (books considered classics or which never go out of print, like Tolkien, Catcher in the Rye, books which are routinely assigned fro summer reading, etc) because the list would quickly stagnate, since those books are always bestsellers, or recurring bestsellers. That part I understand.

The other argument was that they get their information from stores which volunteer to report the numbers. The task is described as complicated, taking 8 hours or so a week. I'm told that if they were to make the task more complicated by asking for information beyond just the newest books, they fear they might lose volunteers. That's the semi-official word. Link to NYT Book Review