Back then (and to a lesser extent now), people tried to make commonly-typed commands as short as possible because keyboards were so beefy, and finger fatigue wasn't uncommon.
It's why the core Unix shell commands are things like "cp," instead of "copy."
This has a lot more to do with how slow the ASR-33 teletype was/is.
Picture a group of humans who evolve a new language. That language will likely start with short sounds, and then progressively build up to longer sounds.
https://www.youtube.com/watch?v=fCn8zs912OE
Anyone who hasn't read A Mathematical Theory of Communication, you're missing out. It's quite readable and quite cool: http://math.harvard.edu/~ctm/home/text/others/shannon/entrop...
I guess TI, GE and HP were smart to grab them when they could!
There used to be an old site that visualized the two- and three-letter domain name space as two- and three-dimensional grids. It was neat seeing the pixels fill in over time.
Two-letter .com domain names were never reserved. It was possible for anyone to register them in the very early years of the Internet (from 1985 to 1998). The first company to own an active Two Letter Domain is Hewlett-Packard. Since 1998 all permutations of the 26 × 26 = 676 .com domains have been registered and (barring the very unlikely event of a lapse in registration) they can only be obtained by buying them from the previous owner.
https://en.wikipedia.org/wiki/Single-letter_second-level_dom...
Numbers are not letters, but you're right, that's the correct number of possible two-character .com domains.
I remember thinking domain names were for people who "really knew what they were doing" and then was pissed I didn't register one before NetSol started charging (IIRC there was a big outcry because Kraft foods registered like 137 domains right before they started charging).