"a simple file sharing server on their own PC or a server they own would do the job just fine"
For your own sake, I hope you get more real-world experience before making investment decisions or building technology to sell. To you, somehow the existence of a massively profitable, multi-billion dollar company must be evidence of people's irrationality and not an unmet need.
Are they "massively profitable" though? I haven't really heard anything regarding their financials. They're well funded, but that doesn't really mean anything these days.
There's certainly a need, don't get me wrong. It's just that for most people (paid) dropbox is the wrong solution. And at some point the right solution will present itself and suddenly dropbox will see its market disappear.
As a private company the financials are private of course, but take this as you will:
"Dropbox’s ascent has been just as stunning. The 50-million-user figure is up threefold from a year ago, and it has solved the “freemium” riddle, with revenue on track to hit $240 million in 2011 despite the fact that 96% of those users pay nothing. With only 70 staffers, mostly engineers, Dropbox grosses nearly three times more per employee than even the darling of business models, Google. Houston claims it’s already profitable but won’t reveal margins."
But has the percentage of premium users stayed constant as they grew? I wonder what percentage of users must be premium for dropbox to be/stay profitable. Or perhaps what percentage of traffic must be "premium traffic". Either way, there are a lot of unknowns, but I don't think this market is sustainable. Like Jobs said, dropbox is a feature, not a product. They are able to exploit a market inefficiency for the time being. I don't see that lasting for much longer.
Dropbox's long term future rests on them evolving into something that isn't easy to duplicate or pre-bundle. And even then, unless dropbox pivots massively, the market just won't be as big. File sharing simply is not a multi-billion dollar market.
(I can't help but wonder who I'm talking to seeing as you whipped out a throwaway for a dropbox discussion thread)
For your own sake, I hope you get more real-world experience before making investment decisions or building technology to sell. To you, somehow the existence of a massively profitable, multi-billion dollar company must be evidence of people's irrationality and not an unmet need.