I've tried doing this a few times. It doesn't always work very well. I had someone tell me "I want Pomegranate! If you get it, I'll buy from you and no one else." As someone I was more then acquaintances with, I said "Ok, I'll get you Pomegranate!" Well, don't you know, I bought it, she HATED it and I was stuck with it! Luckly, I didn't buy very much, but nonetheless. It's impossible to please everyone. Look at a scent like vanilla. Everyone has their own idea as to what a "good" vanilla is and that could encompass dozens of different types. I agree though with the idea of taking notes and seeing if there are any trends. If lots of people request "warm apple pie" let's say, then maybe it's something you should add. If someone REALLY wants that custom order and they're willing to wait for it, then maybe it's worth it.