Ok is my idea over-used? Granted I don't think I know of another advertising site trying to be the widest in the world but will this fail? http://www.expandy.com Also what is your comments on it's name?
Are those sites you added to website? That is a good start if they are buying customers. I would def get adwords or 7search going on this site ASAP! It's a brilliant idea that should draw a crowd. Why did you put a limit on sites, 5000? I wouldn't even put that there. Do you require a reciprical link? That would def boost your potential for the site. Nice so far, good luck in the venture!