Jordan Koschei, writing for The Industry on Dropbox’s “get free space” push to have the user complete extra steps after first signing up:
This solution is much more elegant than simply forcing users to sit through instructions. For one thing, it offers them a choice; nobody is forced to go through the steps, but most people will anyway in order to gain the reward. Furthermore, the reward is intrinsically linked to the product — it isn’t a tangential incentive like a badge, but rather more of the product itself. Rewarding appropriate use of a product with more of the same product is simple and elegant.
Dropbox’s approach is novel. I know many non technical people who still rely on Dropbox everyday for syncing critical files between multiple computers. I never would have guessed that such a hard to explain, engineering focused product would have such an elegant setup process, but they do.