In a recent workshop, Bob Buch, VP, Business Development at Digg.com, said that "social community sites using Facebook Connect API have seen their traffic increase from 30 -100%"

Facebook connect provides an easy to use api for developers to allow their customers to use their Facebook user name and password to join a community without having to fill out a registration form.  Once registered:

1. Profile information is pushed from Facebook to the new community.
2. Content can be synchronized, so photos, videos, status updates, etc... can be posted to Facebook and to the community from either Facebook or the community.
3. Users can look up Facebook friends from the community and invite them to participate.

In the following video, Robert Scoble interveiws Luke Shepard, a Facebook software engineer, to find how to set up the Facebook Connect comment option for web site or blog owners.  Many social applications already have widgets that make it very simple to use Facebook connect.

With more than 150 million monthly users, Facebook is an excellent community for companies to partner with and leverage Facebook connect to provide niche communities and services to Facebook customers.

Some example of sites that have benefited from Facebook connect integration include:

Prototype Experience - Lets users see Facebook profile information and pictures within the vide game demo.

Beware of the Dog House - Lets users see Facebook friends and decide which ones to send into the Dog House if they misbehave.

For my own mini experiment I have added Facebook connect capability to Social Bean Bag.  So you can register using your Facebook account and immediately make a comment.