Email is the Ultimate Social Network: Watch out Facebook and Myspace.

MySpace and Facebook are generally accepted as the largest and most popular social networks on the Web; but I would like to propose that this is a misconception. The largest and most popular social network is….YOUR EMAIL ACCOUNT.

Most of us have been using email long before Friendster came and went and Facebook rose and shined. Over the years we have collected hundreds and thousands of contacts. We communicate with these people regularly through email. It is likely that we have not even met many of these people in person. It is likely that we were connected to some of these people through others that are already in our contact list.

The problem with email as we know it today, however, is that it does not do a good job of unhinging the underlying social graph within our contact list. Helping people connect to friends of friends and exposing personal profiles of these contacts has been exclusively the role played by social networks. But that is about to change.

Xobni (Inbox spelled sdrawkcab…I mean backwards) is a new startup that has created an add-on application to Outlook. Xobni not only helps you to better organize your email and contacts, but it also tells you everyone in your contact list that has sent an email to each other…it “expose the hidden social network” in your email. It therefore connects your entire contact universe, even if certain contacts are not in your MySpace or Facebook friends list.

Xobni is simply brilliant, and the Valley Behemoths Yahoo and Google agree. Both have announced plans to add features to their existing email and personalized home page services that resemble the key attributes of many social networks.

While Google is holding its card close to the vest, Yahoo has been more forthcoming. They claim to be testing a method that can automatically determine the strength of your relationship to someone by how often you exchange e-mail and instant messages with him or her (very Xobni-esque). For those who opt-in, Yahoo will share contacts and display personal profiles in a similar fashion to Facebook. According to Brad Garlinghouse, VP at Yahoo, “The exciting part is that a lot of this information already exists on our network, but it’s dormant.” Consequently, adding social network-like features is a natural evolutionary step for email service providers.

Given that Yahoo and Google/Gmail already have hundreds of millions of users, I think with time, they will prove that email is, in fact, the ultimate social network. Factor in the instant messaging services not currently offered by most social networks, Facebook and MySpace may find themselves playing catch-up with the Big Boyz.

For more information on this subject, check out Saul Hansell’s article in the NY Times, “Inbox 2.0: Yahoo and Google to Turn E-mail into a Social Network.”