Just a question about Yipit... don't they need millions of visitors to be successful?

100K visitors/month sounds nice, but they're in the deal aggregating business, so the margins are even less than if they were a deal site. They don't make money off every single user, and when they do... they make a tiny percentage as affiliate commission. Am I missing something here? I know regular old-fashioned coupon sites(like CouponCabin) that make good profit, but they have visitors in the millions, and their margin is much more.