The benefits of in-game stores are "pretty clear" for those who already spend on pets and mounts, as you don't need to leave the game. Convenience is the "long-term goal".
Bashiok admits there's "quite a bit of work involved" in retrofitting the game and items to support this new endeavour. Also, any XP buff items are initially for Asia.
"We’re still pretty early in the exploration process, but we did want to go into more detail about our rationale for introducing an in-game store, as well as provide some insight into what you might ultimately see available there," Bashiok.
"For players who are already interested in the in-game items we offer, such as Pet Store pets and mounts, the benefits of an in-game store are pretty clear. We think everyone would appreciate the convenience of being able to make such purchases without having to leave the game, and ultimately that’s our long-term goal for the system, though there’s quite a bit of work involved in retrofitting those existing items into the new system."
"First, we’ll be testing the in-game store with some new kinds of items we’re looking into introducing (in Asian regions, at the outset) based on player feedback: specifically, an experience buff to assist with the leveling process, as well as an alternate way to acquire Lesser Charms of Good Fortune."
They continued: "We’ve had a lot of requests from players in different regions for convenience-oriented items such as these, and as with other new ideas we’ve introduced as WoW has evolved—including Pet Store pets, mounts, and more—your feedback plays a hugely important part in determining what we add to the game."
"Ultimately it’s still too early in the process to make any final determinations about our plans, but in the meantime, we hope you’ll check out the in-game store once it’s implemented on the PTR and let us know what you think."
For us Westerners the in-game store will be a more traditional MMO shop where we spend our real money on cosmetic stuff, because we're so proud of our vanity here in the Western hemisphere. Social peer-reviewed hierarchy FTW!
Already World of Warcraft exhibits free-to-play features, such as enjoying the MMO at no cost up to level 20. We learnt a little while back that Blizzard wasin the PTR.