75% of Dropbox users are located outside the United States. They have invested heavily in expanding their PoPs and in Europe and Asia. https://techcrunch.com/2017/06/19/dropbox-announces-massive-...
The last few years Enterprise customers have been a major target.
https://www.recode.net/2014/3/20/11624780/dropbox-zeros-in-o...
https://techcrunch.com/2016/11/16/dropboxs-latest-announceme...
Again S-1 should provide a peek at the rate of adoption. Anecdotally I can share reports of wavering between consumer and enterprise focus.