When you link to another social network, you can share updates between Yahoo! and the other network. You no longer need to go from one site to another to see what’s going on with your circle of online friends.
Currently, you can link your Yahoo! account to Facebook. When you do, you’ll see your Yahoo! updates on your Facebook Wall, and your Facebook updates added to your Yahoo! updates in a number of properties such as Yahoo! Pulse, Yahoo! Mail, and Yahoo! Messenger. If you allow it, you’ll see your Yahoo! updates on your Facebook Wall. Your Facebook friends and your Yahoo! connections will also see these updates when they visit your profile or Wall.