Until today, Apple’s Mac App Store did not feature support for applications that were purchased outside of the App Store, even if the software was available for purchase in multiple places. However, the Mac App Store could detect whether an application had already been installed on a Mac before it was purchased through the Mac App Store.
Today, Macworld reports that the Mac App Store now prompts users attempting to purchase apps that are already installed on their Macs but purchased from outside the Mac App Store. However, The Next Web notes that existing app and the Mac App Store must be the exact same version in order for the warning to be triggered. The warning reads:
[App name] is already installed and was not purchased from the Mac App Store
Do you want to buy [app name] again?
Even though users are prevented from buying the software and presented with the warning, Apple still offers the user to purchase the app again.
The Mac App Store launched in Mac OS X 10.6 Snow Leopard, earlier this year, and continues to be a major success for Apple. In addition, it is a major selling point for Apple’s latest OS X 10.7 Lion.