Dropbox has 175 million users, up from 100 million in November 2012. I’m certain that this impressive growth stems directly from an upgrade path that is endemic to the product itself.
The way that Dropbox works is that it synchronizes files across different computers and different accounts. So, I have an account and post a 200MB file to a directory there. I share that directory with a colleague in, say, Greece. First, he needs to have a Dropbox account. Then, as soon as his machine synchronizes, he actually has a local version on his machine. The 200MB file takes up 200MB in my Dropbox account _and_ in his.
What’s brilliant about this (from a business perspective) is that this forces users into upgrading from the free version to the paid version because, if you don’t upgrade, you will lose out on files that friends and colleagues are posting to spaces they have shared.
While this is business brilliant, I wonder how many of those newly minted 75 million users feel at least a vague sense of dislike for the company, at least an unease that the company is forcing them to spend money.