In college, I met my future ex-husband through a friend, Joe. Joe introduced two other friends of his who are now married. Years later, he met one of their other friends, and they formed a relationship that lasted several years. None of these were fix-ups, just friends meeting friends.

When my sister was backpacking after college, her college friend told her to look for his good friend from high school, also travelling. They did meet, and have been friends ever since.

So there’s some logic to the sites that let us know how many facebook friends we share with our match. But we all know that “facebook friends” are not necessarily our real friends. They may be acquaintances, or people we met once. They may be people we worked with, or someone we knew very, very well a very, very long time ago. Our old babysitters and teachers. Our kids’ friends and friends’ kids.

Friend of a friend on facebook is not equivalent to joining mutual friends for some shared experience. If you’re at your friends dinner party, your hosts considered how the combined guests might connect for comfortable and interesting conversation. Not so with random and broad facebook connections.

There’s a potential downside to the mutual friend. Maybe that friend is an old flame. Or you don’t intertwine your work and social relationships. And, if your shared friend knows you’re dating and knows “he’s” dating, why haven’t they thought to introduce you? Or did they, and then decide against it? Why? What if the mutual friend is uncomfortable answering your questions about your match?

Of course, it’s possible that the mutual friend connection could play out well and help things along. Like when we have mutual love for dogs and Italian food, a proven formula for success.