I qualify for #1, #2, and #4.
1. You have small ears and have trouble using normal IEM
My ear canals are extremely small, and most earphones I use always fall out. For example, I can't even get the apple earbuds in. Right now, I still can't find a right fit with my Turbines. It would be extremely nice to have something for small ears.
2. You sometimes listen to your music while you are sleeping
I always listen to music to help me fall asleep xD