I had one of those ‘cold shivers running down your spine’ moments this week, when a simple Dropbox problem wiped out an entire client Xcode project. I’m not entirely sure why it happened — I assume because of my constant rebooting between Snow Leopard and Lion (and subsequently ‘out-of-time’ file dates), but by the time I realised what was going on, neither Dropbox nor Time Machine had a copy of the files. Had I not set up three levels of backups, I might as well have been burning incense to the gods to get my data back (did you like that? I tied the pretty photo I took to the words on your screen!).
Thankfully, Backblaze was far more thorough than either of these services and 5 minutes after running through the online restore wizard I had a full copy of the project on my hard drive, and was knee deep in code again. Thankyou, Backblaze — you saved me stress and time, and the $5 (well, $4-something Australia) per month to backup my Mac is something I will not question again.
If you rely on your Mac professionally, and you keep anything remotely important on there please take the time to verify the integrity of your back-ups.