I interviewed with a friend for the first of three interviews. It involved watching videos talking about how great Apple is, asking everyone what they liked most about Apple and what products they had, and role playing based on cards describing certain scenarios. I made it through to the next round, but my friend unfortunately didn't. I was surprised, especially considering her retail experience.
The second interview was a 2:1 interview with the Senior Managers. It was honestly really laid back and I was just being myself. Having a sense of humor helps, too! They asked what Apple products I had and each had one question, which were typical textbook interview questions.
I then made it to the third interview, which was basically the same as the second, but with the Store Leaders and Market Leader (3:1). Again, what Apple products I have, etc. Then a question from each member. Textbook interview questions again, but I think the key to answering these are to relate it to the Apple environment. One of my questions was: Name a time where you felt you were right about something while everybody else was wrong. Not sure if that's what got me crossed off their list, but I could have answered that better. I hesitated and thought hard, and actually came up with a situation, even though I'm really the type of person to hear out people if there's a majority of people who think they're right and I'm wrong. The psychology and nerves got to me.
We also talked about full-time/part-time opportunities, and it seems that they mainly hire part-time and you gradually move into full-time. A lot of work for a part-time job, but they do treat you well, as seen from my brother working there.
I really think the key is just being yourself and don't exaggerate too much when it comes to your Apple products, except maybe in the first interview. You can wear jeans, as long as they're dressy. Look in an Apple store before you interview and dress maybe a notch higher than what you see there. I also think it simply comes down to luck in the end, seeing that my very-similar-in-personality brother got in, and I sold him on Macs. It's a competitive and great company to work for from what I've seen him go through, but they simply had to cut someone.