Interesting move: Blizzard, who has already sold in-game items like player mounts and animal companions for subscription-based WOW (but through channels outside the game), is now introducing an in-game storefront. The new system,will be tested in Asian regions first and offer convenience-oriented easier progress through the game, such as experience boosts.
Full story: World of Warcraft opening in-game microtransaction store | GamesIndustry International.