Twitter has created an experimental account, @MagicRecs, that will DM you recommendations on whom to follow. It looks at your current network, studies your and your friends' usage patterns, and provides recommendations on whom you should follow.
The draw for users is that they would "receive realtime, highly-relevant DMs about accounts to follow and tweets not to miss."
If some of the recent tweets about it are any indication, it's working quite well:
At this point I follow everyone @MagicRecs suggests.
- Todd Johnson (@todd534) September 14, 2013
You should be following @MagicRecs. It has fundamentally improved Twitter for me.
- Chris Sacca (@sacca) September 5, 2013
If it catches on, it can also benefit businesses that successfully engage Twitter followers - the more you keep them engaged, the better your chances of being recommended to their networks. It also seems like you won't have to pay for these recommendations (for now).