I used BackBlaze for a while before I switched to Linux and it worked pretty well. At one point I wanted to download a lot of my files at once and the 80GB zip file they provided didn't work, but I was able to download it in smaller pieces. I think that by limiting file size, not providing a Linux client, and not backing up network drives they try to avoid some of the largest storage consumers.
Good point. Also, unlike others I'd tried in the past (iDrive, Carbonite), you don't have direct access to your backed up data.
You essentially file a online "request" to retrieve this or that file/folder and wait for their email to tell you where to get it.
It probably allows them to store the data in a more compartmentalized, potentially cheaper, environment. Since most people will almost never attempt to restore data, it's not a big problem.
