Edward Castronova: Synthetic Worlds : The Business and Culture of Online Games
I've just started reading this book but am very impressed with what I've read so far and recommend you buy the book and explore for yourself, especially if you have young children (I'll follow-up with other posts if I lose interest in the book for any reason, but I believe even the intro chapter is worth the ~$19 at Amazon.com). Book reviews can be found via the author's site (the primary link for this post). It usefully complements Smartbomb (which I impulse-purchased following an Amazon.com offer/suggestion for both when I bought the Castronova book); the latter is a primarily series of biographical overviews of some of the key people who contributed to the game business, while the former is a more comprehensive perspective from an economist who's also an excellent writer (and apparently an avid gamer).
(Yes, one of my New Year's resolutions was to read more books...)