I think this is often not true, and the examples in the post show that.<p>People had already been willing to put their real names online. Friendster launched 1-3 years earlier, grew very fast, and if they hadn't been alienated their users and been hamstrung by technical problems, they might have gotten to be Facebook.<p>Airbnb is a great company, but VRBO.com had been around since 1995 and is now going public (as part of HomeAway) -- they did pretty well through the real estate boom. There was also Couchsurfing, founded about 5yrs before Airbnb. Could they have been Airbnb? They succeeded at getting users, so I think they were only missing two key pieces: they hadn't realized that if you charged people to stay you had a great business (or didn't want to do that), and they weren't very good at making backups.<p>Of course Dropbox had a whole forest of competitors. I don't think Box.net or Xdrive or whoever failed to become runaway successes because people didn't have enough devices - there were millions of geeks with multiple computers and there had been for years. And there was plenty of broadband: YouTube had already been around for 3 years. Dropbox succeeded because they made syncing easier to use, and because they marketed that better than anyone else.<p>There are definitely some startups that couldn't have succeeded a few years earlier, (like the Zynga example which needed the FB channel to exist). You couldn't have made AdMob any earlier because a lot of people needed to go buy smartphones. You might have been able to build YouTube in 2004, but not in 2002, because you needed broadband penetration, fast computers, and a Flash player that could stream video.<p>Sure, riding a wave or exploiting market trends can be helpful. I think a lot of great products could have been built much earlier though, and the limiting factor is often simply that it's difficult to know what's important, and difficult to get the important things right.
Good article, but I think the reference to Dropbox is a bit out of place.<p>Online backup/sync, which is what Dropbox does, was readily available when they arrived. The thing was, nobody was using these services because they were not straightforward enough to set up, or were too costly, etc. Dropbox "got that right", so to speak.