The Mac OS X App Store is coming down, but unfortunately I'm afraid we will have to go little by little, and the bad news about absences is coming to light.
To begin with, it has been known that Apple is not going to launch Game Center on Mac OS X, so there will be no gaming platform for Mac, in an obvious move for people to play more on their iDevices.
On the other hand, it has been confirmed that application promocodes cannot be given on Mac OS X. And why is this? Well, basically it is not understood, since the operation is the same as in iOS, so let's see if they rectify ...
Source | Mac Rumors