I don't think thinking about "the next big wave" gets you anywhere either. Zuckerberg and Anderson didn't figure out that social networking was going to be big

I don't think thinking about "the next big wave" gets you anywhere either. Zuckerberg and Anderson didn't figure out that social networking was going to be big - they invented it instead. When you think about it the basic idea isn't even remarkably clever. However, it turned out keeping track of friends online was really compelling for people. I have to believe this came as a surprise to them as well. As always, the trick is to think about a problem you're having and to build something to solve it (a cliché at this point). That's certainly what Zuckerberg did with Facebook, which is why it was initially aimed specifically at college students at specific campuses. He was scratching his own itch. The rest of Facebook's story is one of coincidence and evolution.