I'm selling my old laptop and I know to deauthorize the iTunes account but do I deauthorize my Mac App store account? Even if I reformat the drive, the hardware still has to be deauthorized for iTunes. Is the same true for the Mac Apps?
You can open the Mac App Store, go to Store > Sign Out. To deAuthorize your account you will need to open itunes go to the itunes Store and click your account in the right corner and there will be an option to deauthorize All your computers. Thats should be enough.