Credits just allow you to contact the women by their email system or CHAT via their IM system (i havent tried that yet). If you don't buy any credits all you can do is browse. At least you can browse to see if there is a woman that interests you before you buy the credits.

If you do an advanced search you can search for women in your area that are "Online right now"... or you can search in an area you plan on visiting soon, like on a business trip

EDIT - i'm actually spending way too much time on this site haha

EDIT2 - also, there are some definite gold diggers. You can tell them a mile away bcuz in their profiles they say things like "INTERESTS: being pampered, taken shopping, nice dinners" etc.