Most skydive operations require a commercial pilot certificate. A skydive pilot should be getting paid.
The exception that I see is if your good friend is a skydiver and you want him to jump from your plane. Think of it this way, if the skydiver wasn't going to pay to jump, for example friend-to-friend basis, then maybe you could do it. But most skydiving ops and drop zones are for-profit or clubs where members are paying some sort of load fee.