Utilize Facebook's Open Graph for shareable content
Web sites and web applications have become increasingly interactive and can adapt to the user's personal preferences. However, in order to do so, the user is required to login so that the web site can retrieve the user's personal preferences.
This quickly became tedious and cumbersome for the users as they would have to sign-up for different web sites, go through the hassle of e-mail confirmation, and then (worst of all) remember what login name and password they kept for each different web site.
With Facebook Connect, all of that can be eliminated, along with receiving several additional benefits.