First you need to get girls...
no wait
First you need traffic to keep the girls
or
You need girls first to convince affiliates to give you traffic...
-this is one of the enigmas your friend will face-
Tell your friend it will be a long and painfull road. You need a lot of money in the bank, a lot of patience and you need a couple of people working really hard to make it work.
No short answer to that question.