I'm sure most of us know about the phenomenon that is group buying, with the likes of Groupon, Living Social and a host of others out there taking advantage of it. There's one thing that these sites have proven, which is something that has been known all along and that is "there is power in numbers." Those who have used these sites would pretty much know the concept and how the companies operating the sites implement the concept. Groupon as an example, has thousands of sales people around the world who go to merchants looking for daily deals they can sell on their site. I would imagine others operate similar to Groupon.

In the B2B space as well, there are sites like OfficeArrow, BizyDeal, OfficeDeal and others that have bought into the group buying concept. Unlike Groupon and other consumer based sites, these sites are more focused on business to business.

Whether B2C or B2B, the concept of these buying sites is all about supply. Make sure there's a steady supply of deals, and demand will build itself. Has a bit of a ring of that saying in baseball, "build it and they will come."

There's a concept that's also coming up as well, which is the opposite of the supply initiated group buying. The concept is about focusing first on the demand, and then letting the supply build itself. Unlike the well known concept where a merchant publishes a deal and buyers buy into it, demand initiated group buying works opposite where buyers publish requests and merchants compete to win the business. It may seem like it's not group buying, but when a request is published, other buyers who may want the same thing will join the request, creating a pool of buyers that merchants would want to supply. The concept works similar to that of co-operatives in the brick and mortar world.

There are a couple of sites that have been recently launched in this regard. One of them is Obaz (obaz.com), which creates groups of people wanting to buy similar items. Like Groupon and Living Social, it operates in the B2C space. In the B2B space, there's Bequester (bequester.com), which also gets businesses to publish requests for bids that other businesses can join and merchants can bid on, competing to win the business.

The question here is, will demand initiated group buying catch on? Will it spread like wildfire in a similar manner as supply initiated group buying?