Twitter's new Activity feed

Today Twitter launched a new Facebook-style 'Activity' tab where users can view a stream of their followers' recent Twitter action.  So you can see who your followers have recently followed, who they have added to lists, or what tweets they have added to their favourites.

Additionally, the 'Mentions' tab has been replaced by a "@username" tab.  Here users can see an activity stream of those people who have retweeted, mentioned or followed them. 

The Activity tab is a neat feature that gives users a better sense of what's going on in their follower community.  No doubt it's designed to ensure continued follower-growth, but it will be most useful for brands & businesses.  It will give brands extra reach because every time they are followed the 'Activity' tab allows a much wider audience to be exposed to that brand interaction and to potentially follow that brand themselves.