Over the past six years group buying had grown into a multi billion (US) dollar business. Among the many sites focused on group buying around the world, Groupon.com is the largest with global presences in 24 countries or 168 cities, and Woot.com pioneered the concept when it started in 2004.
If you are not familiar with group buy please allow me to explain, the concept is fairly simple. A merchant (shop) subscribes to a group buying site (site). The shop creates an offer for it’s services or products at a discounted price; something that is very attractive (around 50% off or more). The shop specifies a minimum number (tipping point) of sales for the offer before it becomes valid. The site will then list the offer along with customized marketing copy on its site and all channels the site has at its disposal.