I actually just answered within the context of sharing within a family... I also have my MacBook air, the agency Mac pro I use everyday, an agency iPad (used fo

I actually just answered within the context of sharing within a family... I also have my MacBook air, the agency Mac pro I use everyday, an agency iPad (used for iOS dev and website testing), and my daughters old iPod touch all using the same Apple ID! I'm really surprised that Apple allows 10 devices to share one ID. It's saved me a lot of money, but I certainly spend my fair share of it in the app store (~$300 this year).