The eagle-eyed Matteo Bittanti points to a New York Times article discussing the state of the book-based video game strategy guide, including a number of interesting points.

In particular, BradyGames' success with the GTA strategy guide is made explicit: "The guide for Grand Theft Auto: San Andreas, an intricate and violent action game, has sold 748,000 copies, an unusually high number, since it came out in 2004. [Prima Games guide writer David] Hodgson estimates that the 55 strategy guides he has written have sold a total of one million copies."

Overall, one of the article's main conclusions, while noting that online resources may be eroding the market, appears to be that: "Video games are not usually associated with reading, so the strategy guides' popularity is something of an oddity, marrying the fast-paced, fast-twitch world of computer and television console games with the tactile and ruminative experience of text-centric manuals." We're still trying to work out if this is a fair and/or positive comment or not.