Blame the disk storage vendors:
They sold a 40 MB drive that stored "(at least) 40,000,000 bytes". When we assumed we were
buying a MiB drive, and found a MB drive, we felt cheated ... by 4.86% !!!
Lately, with *GB drives, the difference was 7.37%.
With the impending *TB drives, the difference is 9.95%. "Caveat emptor" and all that, but
(Disk for sure, maybe tape ... not RAM ... surely? Better check those SSD's carefully, eh?)