It's an easy way to stay in touch with social networking websites like Face book. Instant communication to the masses with the possibility of more than one potential conversation awaiting to erupt seems to be appealing. Some other factors could be that you can log in for just a few minutes a day and catch a snippet of every one's life if they choose to share, there are also online photo albums for friends to view your adventures instantly. Face book messages sometimes seem like they are the new 'email' correspondence system, only shorter. Face book "invites" easily take the place of phone calls - when trying to organize events as they are less time consuming... Groups that connect you to like minded people...
I don't know - Face book is okay, but I really like real people and I really like snail mail and handwriting and sealing wax...