How Dropbox is different from hundreds of "storage in the cloud" companies ? All of what I saw in the slideshow I might assume was more or less done by the other companies. General marketing fluff that is quite obvious.( Nothing against Dropbox, since I'm a happy user). Luck played a certain part(big part?). I want to see the slideshows of companies that took years to get to 100,000 users :) Then I might think they had less luck and their lessons would apply to your average startup.
Patrick McKenzie for example (no offence), I don't think he was lucky it just lots and lots of work and I get real gems from his talks/blogs...