Eyeballing this chart: https://en.wikipedia.org/wiki/File:Hard_drive_capacity_over_time.svg https://en.wikipedia.org/wiki/File:Hard_drive_capacity_over_... It

Eyeballing this chart: https://en.wikipedia.org/wiki/File:Hard_drive_capacity_over_time.svg https://en.wikipedia.org/wiki/File:Hard_drive_capacity_over_... It looks like over the past 8 or so years you're looking at a maybe a tripling in capacity. Cut the size of the truck down by a third, accounting for the fact the truck couldn't have been stuffed with every cubic inch being hard drive due to the need to walk in it, weight limits, cooling, wiring, etc., and I think it's not hard to see that even if it did make sense at the time, it's not hard to run the numbers and build some 4-6 U storage units and ship those instead. Even if you ship 4 of those it's cheaper than a truck by quite a bit. Also, if you're willing to spend the dough, flash density can be pushed even higher, I think. You might need some custom hardware to manage power to the drives, so only the drives the customer is filling right now are powered (heat management is going to be a big deal with flash), but that's not impossibly difficult. You can even drain an entire data center by cycling the same 3 or 4ish units around. Fill one up, send it in, Amazon loads it up, send the same unit back. Even if it takes 10 loads you don't necessarily need 10 hunks of hardware. Personally I have the sneaking suspicion that it was always a marketing stunt and never actually made monetary sense. It was just a grand gesture to reassure people that they could indeed move to the cloud, which was a large concern for a lot of large customers. In that sense it probably paid for itself. And once you do have it in hand, maybe the marginal costs are still attractive and you go ahead and use it sometimes. But I'd personally bet the "round robin of 4-6U storage racks" would always have been more economical regardless of hard drive densities.