First Apple made Twitter and Facebook sharing available in iTunes. Then came the App Store on Facebook, and Apple started creating country specific pages for iTunes. In Twitter, it was iTunes’ category specific accounts that apple created. Thus slowly Apple started to use the full potential of social media to promote its products.
Thus finally ended up creating a Twitter account for the App Store. Apple has said it will promote new apps and some offers, and may even giveaway promo codes through their App Store Twitter account.