The file backup and sharing service Dropbox is hitting a milestone. It has reached 25 million users and 200 million files are saved daily with more than 1 million every five minutes. The growth is astonishing, just last year the company only had about 4 million users. The idea of dropbox is rather simple. It enables people to sync files and media across platforms and devices, and in order to have them available from any location. Dropbox also allows users to easily and efficiently share files with other users and you get 2GB of free space and can pay for more if you have an extensive library. These types of services are awesome and very useful. It would be interesting to see what type of revenues they are getting from customers that go over the 2GB. With 25 million users and 200 millions files per day I would say a good chunk of those people are paying something.