There is a potentially infinite number of actions one has to do right, in order to succeed with the next big thing. Facebook have had, and still have, some competitors.
It might be that it is actually harder to create a company that way. By definition, the next big thing is not fully understood, what increases the probability of screwing up badly.
And, it's not that obvious whether such model yields the highest returns, to put aside the risk reward equation. We still don't know whether Groupon or Facebook will become long-term profitable companies.
Also, in so fuzzy environment, it's extremely hard to get the timing, and assets, right. The idea of consumer cloud, as syncing the data automatically between many dummy clients, was obvious since 70s, and it actually took enormous efforts from Apple, like iPhone and iPad.
On a much broader perspective, I remain unconvinced that the next big thing is what gives the society the most innovative fruits. The idea of tablet was so cliche everyone gave up, and I'd say that iPad itself is worth much more than the Apple's cloud.