Grapevine, Texas-based mega-retailer GameStop reported its second quarter fiscal year 2007 results today, which included a 586% year-over-year increase in earnings to $21.8 million. The company's revenues totaled $1.34 billion for the quarter ending August 4, a 38.9% jump from the same period last year.

As usual, GameStop's used game and hardware dealings brought in the bulk of the earnings for the retailer--the $173.2 million in profits made up 48.5% of the total earnings. The company has been criticized by developers for making used game sales its bread and butter, as well as its toast and jam. Though total used product sales increased just 16% in the quarter, new game software sales and new hardware sales rose 49% and 87%, respectively.

The top-selling software titles for GameStop during the quarter were Harmonix's Guitar Hero II (PS2, X360), EA Tiburon's NCAA Football 08 (PS2, PS3, Xbox, X360), Hudson Soft's Mario Party 8 (Wii), Game Freak's Pokémon Diamond and Pearl (NDS), and Turn 10 Studios' Forza Motorsport 2 (X360).

Because of the second quarter's high revenues, GameStop has increased its guidance for the fiscal year, estimating a 20.0% to 22.0% increase in total sales. GameStop now operates 4,954 stores in 16 countries, according to a release accompanying the earnings statement.