As much as I like DropBox, you have to take dl.getdropbox.com out of the equation to get an accurate comparison, because dl is used for sharing files with third parties and even hosting files on the web.
In general, it's hard to look at web traffic statistics alone for a product like Dropbox because in some use cases, it can be doing its job perfectly without you ever needing to go to the website. A surprising percentage of our active users basically never go to the site!
