Earlier quoted context omitted.
I always wondered, why do small companies use Dropbox at all? A 1 TB NAS in RAID-1 by Synology or QNAP will cost you about 400 EUR (including VAT). That's about 9% of what the author of the article paid for some 700 GB in Dropbox. It will do everything that Dropbox does, except you can use standard protocols (SMB, AFS, WebDAV, whatever) and the data will not leave your company.
It will do everything that Dropbox does Only after a whole lot of hacking and you'll probably end up having to slap a real server in front of your NAS.
I haven't found anything, that Dropbox does that the NAS doesn't. Maybe there is some marginal function, I don't know. But is that hypothetical marginal function worth the 900% price premium (per year) plus reduced privacy?