Facebook has confirmed that it is testing a new feature that will allow any user to subscribe to notifications of another user's activities through the same interface that new comments and accepted friend requests appear in now.
The feature was first reported on by the watch-dog blog AllFacebook. This feature is going to be a big deal. It will facilitate greater interaction between a user and people of interest by placing updates about those peoples' activities in the highest-priority place in the Facebook interface, the inbox with the strongest signal-to-noise ratio by far.
AllFacebook correctly points out that there may be some amount of backlash among users who are not happy to have observation of their activities made all the faster and easier. That was peoples' objection to the creation of the original Newsfeed, though, and that is now the central part of the Facebook experience. It's fascinating that making already accessible information so much more easy to access can make such a big impact on the user experience, but anyone who has experienced the power of web page updates being centralized in an RSS reader knows that this type of technology really is powerful.
Subscription to notifications will help users track the activities of their closest friends and family, and possibly of people they have a work-related interest in, far more effectively than ever before.
The feature may also make users feel more comfortable adding a greater number of friends than they would otherwise, because they know that they won't miss the activities of the most important people in their online lives. That will be good for both users and for Facebook.