Help me out with the math here:<p>1 terabyte costs them $128.41 per year, right?<p>Amazon S3 would cost them roughly $444 per year, if they were using the Reduced Redundancy Storage.<p>The cheapest HD that I see on pcpartpicker (in terms of Price/GB) is the Western Digital Caviar Green 2.5 TB (5400 RPM) for $135.43, which is $0.054/GB. That's $54.17 per TB.<p>If you want a single backup, that's $108.34 per TB. Two backups (3 copies of each file), is $162.51 per TB.<p>So, if I'm doing this right, as long as their HDs last at least 15 months, on average, they have triple-redundancy, and the cheapest price ratio for consumer hardware. And I'm not even counting their power, network, cooling, or puny humans to maintain it all. That means their HDs, if they were made out of the cheapest parts I could find, would have to last significantly longer than 15 months, on average.<p>They're actually doing really good on price, if you ask me.<p>Or am I missing something obvious, or doing the math horribly wrong?