How many "friends" can you really have?

Who would have supposed seven years ago that the newly launched piece of software called Facebook would so quickly become a routine part of everyday life? It was, after all, just one more digital trick purporting to spring us from the dusty confines of our small-town lives and into the sunny uplands of a global village, where we could make new friends all around the world. Some might call this the fulfillment of the tech folks- brash promises that such software would help us stay close to an ever-expanding universe of pals. There are the triumphal claims of those who say they have 1000 or even 5000 friends on their Facebook pages, who claim comrades in far-off corners of the world they have never visited. But is this really true? How many real friends do people have on Facebook?