DropBox vs SpiderOak

Dropbox is a Web-based file hosting service that uses cloud computing to enable users to store and share files and folders with others across the Internet using file synchronization. There are both free and paid services, each with varying options. In comparison to similar services, Dropbox offers a relatively large number of user clients across a variety of desktop and mobile operating systems. DropBox alternatives for enterprise are: Box, Microsoft SharePoint, Office 365.
Online file storage that aggressively deduplicates data, allowing to save everything you upload, including all versions. They provide nice clients for Mac, Linux, and Windows. And they’re cryptographically secure from the moment your data leaves your computer - unless you hand over your password, even the folks who work at SpiderOak can’t see your data.
Face to face in the news:

2013 - Dropbox becomes Email-provider to catch up with SpiderOak

There was so much talk about that Email is dead. That it's an older technology that will be quickly replaced by social services. But people still use e-mail, and Google is not even closing GMail. And a couple of weeks ago a small iOS-app Mailbox appeared. It helps to quickly organize your inbox (not just in folders, but also in time). It's like a combination of email and organizer. Although Mailbox works only on top of GMail, since its launch millions of users lined up to get this app. And then Dropbox acquired it (for $100 million). The first thing that Dropbox is planning to do - integrate Mailbox with its cloud storage, so that when you attach file to a message it would be uploaded to Dropbox and a link inserted to the message. And in the near future, Dropbox, is probably going to launch this app for other mobile (and non-mobile) platforms and link it to more Email-service, or maybe launch the own e-mail service.