If you plan on making a reservation at an Apple Store for help with your Mac computer, iPad, iPhone, or other Apple device, you will now need to have an Apple ID first.
Apple's Genius Bar service at its Apple stores offers a convenient way to get technical help or advice on your systems, from how to use and set them up, to fixing problems and migrating your data from one system to the next. These popular services used to simply require you to enter your name and e-mail address at Apple's Genius Bar sign-up page to schedule a reservation. However, now Apple is requiring you to use an Apple ID to do this.
One apparent reason for this change is to help prevent abuse of the Genius Bar system. It seems scalping of appointment times has been an ongoing practice in some areas, where people will book all the available Genius Bar times and then attempt to sell them at a premium to people who need help.
Requiring an Apple ID will not only allow Apple to not limit the number of appointments an individual can book, but also make it possible for Apple to track ongoing problems and issues with an individual's system so problems can be better resolved. Some people may be skeptical about having their problem history tracked in this way, but it should only help expedite the problem-solving process.
Apple IDs are already required for other Apple services, including iCloud, and to participate on the Apple support forums, so if you already use these services then you will not have to sign up for a new ID when making a Genius Bar appointment.