That’s exactly what Bakshy found. His paper is heavy on math and network theory, but here’s a short summary of his results. First, he found that the closer you are with a friend on Facebook—the more times you comment on one another’s posts, the more times you appear in photos together, etc.—the greater your likelihood of sharing that person’s links. At first blush, that sounds like a confirmation of the echo chamber: We’re more likely to echo our closest friends.
But here’s Bakshy’s most crucial finding: 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. The links from your close ties, meanwhile, more likely contain information you would have seen elsewhere if a friend hadn’t posted it. These weak ties “are indispensible” to your network, Bakshy says. “They have access to different websites that you’re not necessarily visiting.”