Facebook has had an update feature similar to Twitter for a while. Now Facebook has a feature that lets users add feeds from other web services like Flickr and del.icio.us — just like FriendFeed. From a technology perspective, Twitter and FriendFeed are now reducable to Facebook features. Even if those two apps are currently more robust than their equivalent Facebook features, there’s nothing to stop Facebook from copying them in their entirety. So are Twitter and FriendFeed features, or are they companies? Some make a strong case that many of Facebook’s younger core users will never user Twitter or FriendFeed because the same features are available right there on Facebook. Ironically, Twitter’s and FriendFeed’s core asset — arguably their sole competitive advantage — is their people, their users.