I still don't get the idea of "cloud" backup. Not only is it not secure (nothing is), but unless you are graphic or video intensive, you can back up most of your files (even apps) on a thumb drive or disc. If that's not enough GB's, there are cheap external drives for hundreds of GB's, that you can store elsewhere or grab and run. What's the point? Most people don't even use close to the 300 GB's on their own computers.
If you're a file intensive company, then you have your own servers and back up systems. I believe it is a solution to a non-problem.
The European Union is trying to push cloud computing in a big way; even their native businesses and population are still wary of it. Carbonite looked to me like the first vestiges of such an assault on US computing.