I just browsed huddlebuy and like it, I like it alot. They say it is the groupon for small businesses. Group buying works as follows: huddlebuy or groupon or whoever agree on a deal with a supplier – some of the deals require payment via huddlebuy, others require payment on collection – some are free. On purchase you receive an email with all the information you need – i.e. a coupon.
The site makes money from charging the supplier commissions, the user benefits from a discounted price, the supplier benefits from the exposure.