I can't see how Dropbox wouldn't end up getting crushed in this fight. Just recently, they reclaimed all the promo/referral/college storage I had, and shrunk my space from 40GB to 15GB. Pay up $10 per month or lose all your data.
I shopped around, and got a $2 per month from Google Drive. The product is pretty much on parity with Dropbox on the Mac, and works exactly the same way. Yes, I'll take that 80% discount, thank you.
It's mostly, right now, because Amazon's desktop software is _so_ bad. Whereas with Dropbox and Google Drive, I can simply save files to a directory on my computer and can be assured that Dropbox/Drive are uploading them automatically and keeping them in sync, with Amazon, they seem to have forgotten about Sync all together. There are files that I add to the cloud. Should I need to work on them again, then I download them from the cloud, edit them, and add them back.
This workflow sucks, and it's worth paying to not have to do that.
> The product is pretty much on parity with Dropbox on the Mac
In my experience, Dropbox is always faster and more reliable. The other big selling point of Dropbox is the wide adoption of its API. It's basically the de-facto cloud sync solution for most of the iOS/Mac app out there (some are moving to iCloud, but Dropbox is still the more reliable/popular one). If you are deep integrated in the Apple eco system, Dropbox is hands down the best you can go with.
User count - yes; revenue - I honestly don't know. There are quiet periods for restricted stock units for when you might know more than the market. When then quarterly numbers are out the blackout period ends and you can trade your stock. It's been like that in every publicly traded US company I've ever worked at.