I had a friend who donated eggs a few times. As mentioned, it's a process involving hormone injections, no drinking, exercising, and so on. Also need to have a great medical history including parents, grandparents, etc. It does pay quite well... she got $6k-$8k each time.
Donors can choose to be anonymous (the process where they are known after the child turns 18 is NOT anonymous) and furthermore, if the donor chooses the ID option, the parents can still override and choose to have the donor be anonymous.