One of the problems too is that it makes it more difficult to distinguish who is actually interested in being a close friend with you and who is only interested

One of the problems too is that it makes it more difficult to distinguish who is actually interested in being a close friend with you and who is only interested in being a casual relationship. To give just one example - in the past, you might have gotten birthday e-mail from a few people. You would have a sense that these people thought about you enough to pay attention to your birthday and contact you. Likewise, if you cared about someone enough, you could do the same and signal that you thought of them highly as a friend. But now you have Facebook asking everyone your connected with to leave a birthday message on your birthday. I've seen people who's Facebook accounts seem to clearly be dead, but they keep getting the same dozen birthday greetings each year from the same people who actually don't care enough about the person to notice they're no longer on. And since the Facebook birthday seems to be the way a lot of people think about their friend's birthdays these days, not participating means that you're going to get much fewer birthday greetings than you would have in the pre-Facebook days. Again, this is just one example, but I think it does a decent job of illustrating how Facebook has supplanted a lot of more substantive communication and replaced it with copious amounts of junk food communication.