From what one reads on the web, OwnCloud seems to have become quite popular. While I have two small Owncloud servers of my own at home I had yet to see someone else use it, too. And to my surprise it happend faster than I thought.
When I recently passed by the desk of one of my co-workers I noticed the familiar ownCloud design in his web browser. It turned out that it was the ownCloud of a company that wanted to share a number of documents with him without using a public storage provider.
Very nice so now I know for a fact now I am not alone. While Dropbox or similar services would have spared the company the effort to set up their own server it looks like privacy and confidentiality were ranked higher than convenience.