If you fall into misfortune, it's important to have a lot of good friends rally around you. They'll get you through it, right? Nope! If you want to make successful connections, go to the people you barely know.
Good friends are bound up in each other's lives. They form social networks that, primarily, include only each other. It takes time and work to build a friendship, and to maintain one. A group of friends is a closed loop. This loop is closed not only to outside contacts but to outside information. Any information that one friend holds will likely be held by everyone else in the friend group. A group of movie buffs know about all the cinemas in town, a group of clubbers know about the clubs, and a group of academics know about academic gossip. Putting in a lot of time with a small group of people means, unless the solution is immediately on hand, no one is likely to find it.
It's the people on the periphery that lead to new opportunities. They have their own circles of close friends who have knowledge, skills, and connections far outside your circle's domain. They form bridges between circumscribed worlds.
At least, that's what Mark Granovetter thought in 1973. The sociologist did the study and wrote about it in a paper called "The Strength of Weak Ties." Weak ties — casual acquaintances instead of close friends — were more of a resource than strong ties. I would be very interested to see what a study like that would look like today. The internet has changed a lot of things, including who people consider "close friends."
It's possible that all that needs changing about the "weak ties theory" is the definition of "weak" and "strong" ties. It might also be that the weak ties theory has passed its social moment. Perhaps, even though people share specific and consuming interests, the internet lets them cast a wider net. They are able to connect and become close friends with a wider range of people. Then again, maybe all we've done is eliminate "weak ties" completely. The internet allows us to select a more and more specific group of people until we might not even be able connect with anyone outside our little world of strong ties.