My first company, http://www.hoodeasy.com, has worked pretty well using this model. We're a middle-man between clothing suppliers and groups of students. Our selling point is the ease of group-ordering. Our margins are a lot higher than around 3% gross but we have a very niche focus. Another startup in the UK, http://www.wigadoo.com, tried to do lead-gen for group-bookings of holidays and really struggled. They folded around August 09. Group ordering is definitely an interesting space. Sites like http://www.groupon.com have the model just perfect because they focus on facilitating the mass-sale of high-margin products where the fixed costs of those business are quite high. I wish WePay all the best.