By now, the genius of Groupon's business model should be apparent. It requires very little overhead or physical infrastructure because all it sells is a digital coupon over the Internet. But businesses, big and small, are flocking to sell coupons on Groupon's site, given the estimated 15 million users of Groupon in 29 countries around the world that can bring traffic to the stores. Because the daily coupons from Groupon are targeted and personalized to users by city, Groupon would give Google a much needed foothold in the growing, "local market" space to compete with the likes of Facebook.