We've gotten more money from iTunes affiliate links to the application on our page (http://mobile.colloquy.info) than in sales from most of the iPhone-specific review sites that we could see. We've also probably made more sales promoting ourselves and providing support on Twitter.
(Also, for what it's worth this site in question seems to be super slow if you don't pay up $50 or pay for advertising, it's been a little over two weeks with nothing whatsoever. the promo code we sent will probably expire before they review, heh.)