Literature Map?

I found this website (via Flavorwire), called Literature Map in which you type in an author, then it shows you a bunch of other authors who people who like your author also like?  Or something.  I'm not really sure but it's mildly amusing.  I typed in my all-time favorite, Margaret Atwood, naturally, and here's what I got:

Then I clicked on Zadie Smith and got this:

I'm not crazy about Wally Lamb but otherwise seems reasonable.