Q: My brother and I share an iTunes library on a single computer. My brother bought some apps today on his iPod touch and when he plugged in his iPod, his apps were transferred into our iTunes library. I was wondering since his paid apps are in my iTunes computer can I transfer his paid apps for free on my iPod and he could still have his apps on his iPod too?
A: The short answer is yes. You can transfer content from your iTunes library to any number of iPods, iPhones or even iPads, provided the computer is authorized for the iTunes Store account used to purchase those items. The authorization will automatically be transferred from the iTunes library onto the device along with the purchased content. Since you and your brother are sharing the same iTunes library, both of your iPods are authorized for each other’s iTunes Store accounts and you can easily share purchases between them.
While there is no upper limit to the number of iPods that can be synced with a single iTunes library, an iPod can only contain content from up to five different iTunes Store accounts. This restriction is primarily designed to prevent people from collecting protected content from several of their friends, and isn’t likely a problem in a normal household unless you actually do have more than five family members sharing iTunes on that single computer and they each have their own iTunes Store accounts. In that case, iTunes would simply refuse to transfer any content that was purchased with a sixth account.