Ask HN: How does Dropbox attract and steal talent from everywhere?

I've been noticing over the past year that Dropbox has this uncanny ability to get the best of the best to come work from them, whether from other companies (Facebook, Google, etc.), schools (friends from Stanford and MIT have picked Dropbox over other big names), or through acquisitions. How do they do this? It doesn't seem like you'd have the same kind of freedom as a developer as you might at a company like Google.