Who knew they would invent something so addictive. I just read a really interesting article about Newtoy Inc./WWF and the Bettner brothers. Check it, I think you'll find it interesting.
http://www.dmagazine.com/Home/D_Magazine/2010/June/Words_With_Friends_Tests_Your_Vocabulary.aspx
http://www.dmagazine.com/Home/D_Magazine/2010/June/Words_With_Friends_Tests_Your_Vocabulary.aspx