It is clear why some cosmetic manufactures do NOT test on animals? But what is the reason for one's that Do?

I know this doesn't have to do with medicine but I couldn't find another category that seemed more suitable. It is clear why some cosmetic manufactures do NOT test on animals? But what is the reason for one's that Do?
The main reason these days why cosmetic manufacturers don't use animals for testing is because the products they sell are so harmless and have such little effect on the human body that it is not worth the expense. Plus, they can advertise 'not tested on animals' and everyone will think ooh, how caring, I must buy that product. I can't imagine any major cosmetic company still tests their new products on animals.It is clear why some cosmetic manufactures do NOT test on animals? But what is the reason for one's that Do?
I have been trying to research this for a while now. So far I have found a short list of anwsers. I have read that it's to test things like how soft a conditioner will make your hair, or how waterproof a certin makeup is. I have not read anything about how it would hurt the animal in anyway, but I kind of expect that because the big cooperations aren't going to let that sort of information out there to find easily. I'm going to be watching this question to see what other answers you get here.