Facebook is the sixth most trafficked website in the United States, giving everyone access to over 20 million of their users. Facebook is doubling in size once every six months, 100,000 users per day. More than 60 percent of users are outside of college age. By the end of 2007 more than 50 million users if the current growth rate continues, and with more beyond college.

How would it be to market your service or product right here, free of cost! Mark Zuckerberg (founder of Facebook) has stated that ‘You can build a real advertising business on Facebook. If you dont want to run ads, you can sell something. We encourage you to do both.’

Facebook now has a new feature called ‘Facebook Platform’ which allows third parties to create applications and bring their services inside Facebook even if those services compete with Facebooks own features and are making money from Facebook users. Facebook Platform has numerous partners, among them are Microsoft, Amazon and eBay.

So what makes Facebook’s third-party offering compelling and relevant to businesses?

The fact that advertising is no longer the only way to reach Facebook users. Companies and organizations can build applications that users find useful. If people fall in love with an application they can promote it to their friends using the power of the social network. It is a known fact, that a large portion of purchases that people make are based on recommendations.

Facebook also allows developers to include ads in their applications and does not require part of the revenue. Applications can offer content for news feeds, can be added as a box on a user profile, and even added as a link under a user’s profile. This enables a whole new approach to Facebook for companies. No longer are they constrained to a simple group or profile. This is a great new way to introduce folks to a new brand (like Gazhoo has done) or reinforce loyalty to one that’s been around for a while (like eBay has done).

eBay has launched a Facebook application that lets you search for any keyword and returns thumbnails of items for sale on eBay. Apart from the big companies creating these applications, there are small new companies who are also making use of this social graph. For example, Gazhoo, a content marketplace to buy and sell documents, has built an application called ‘Documents’ for Facebook thereby not needing users to leave Facebook in order to make use of their service.

There used to be a time when websites were used to promote one’s business. Now every business is going to need social networking applications to promote their company. Very soon, Facebook applications and social network applications in general will become very common, just like websites.