I know they're so cheap that I can't expect a super quality brand, but are they suitable for the day-by-day (school, work, etc)?
Do they stay for enough time, like a few hours, or do I have to aply it several times a day?

i buy that same brand of eyeshadows. they stay on for a long time, and the colors look real good. they are very inexpensive but they work soooooo good. my favorite is the black one. i have never seen a black eyeshadow go on so dark..