There is no echo chamber

A recently completed PhD dissertation, based on looking at how 75 million links were shared among 243 million Facebook users found that:

Although we’re more likely to share information from our close friends, we still share stuff from our weak ties—and the links from those weak ties are the most novel links on the network. Those links from our weak ties, that is, are most likely to point to information that you would not have shared if you hadn’t seen it on Facebook.

Of course, the former graduate student now works for Facebook, so you may want to take the finding with a spoon of salt.