No thanks I already have kids! If it was to help out some friends that couldn`t do it themselves I would consider it.
What is the obligation here? I'm not looking to become a father but if she has a support system for the baby and so on I wouldn't mind propagating my genes.
An ad? Would I want my bio-child to be raised by a woman who prefers to get semen from an advert rather then from a male friend or a sperm bank? No, I wouldn't answer that ad. Way to sketchy a situation any way that its sliced.