Welkin,
In the past we let everybody signup and just come right in the door. About 75% of the people signing up we cheating or attempting to cheat us or the advertisers in one way shape or form. So what we did is come up with a way of scoring new potential partners. It's not perfect since we do still get an occasional cheater and in some cases we have stopped a good customer from signing up.
So now we just try to verify as much information as you provide to us. Do the domains resolve and where, what address information did you give us, how old are the domains, how many domains, everything you put in gives you certain points, and you have to reach x to get in. So a .com is much better than a .cn domain, but .cn domains would still get you in if you have enough.
Hope this makes sense.
Donny