I worked for three years in a few of my local supermarkets, one of which targeted "people with deeper pockets". Great customer service is what they're looking for, but if you're like me (going for a Genius position) you'll need past experience with OS X/Apple hardware maintenance or other relevant qualification. Windows experience is a plus too.How much experience in sales or retail did you have? Do you think they hire people with no experience? Thanks
Overall, be good and confortable talking to customers (like starting conversations, know when to stop) and know your Apple gear inside out. (Also, they're not looking for fanboys, "I just love Apple" isn't enough, you'll need to demonstrate your ability).
Hope this helps, and if you go for it, dress smart and relax. Best of luck =]