It's an amusing point. As others have noted, in the computer industry the "customer" and the "user" are often not the same person, so we need different terms for them. Of course this is true of many other industries, too. But I think most other industries have more specific words. The person who buys a car is generally referred to as a "customer", but anyone who uses it is called a "driver". Likewise in the publishing industry someone who buys a book or magazine is a "customer", but someone who uses the book is a "reader". The appliance industry does talk about "appliance users". Maybe there are other cases.
Maybe the distinction is more pronounced in the computer business because customers and users are more distinct than in most industries. The customer is usually upper management; the users are usually clerical workers. Well, I suppose you could say the same about many products that are typically sold to businesses. Like, the person who buys a forklift truck probably isn't the person who drives it.
I think this is more an "additional musing" than an "answer". Whatever.
"Hey!" has been in constant use since at least the 13th century (according to OED 1 the earliest documentation is 1225, but identical expressions occur in several other Germanic languages). It's an interjection expressive of, well, practically anything you get excited about, much as it is today: "Hey, you!" "Hey! What a party!" "Hey-hey-hey!"
An 'intensive' variant, "Heyda" (also with continental cognates), is first recorded in 1526, in this eloquent cry uttered by Courtly Abusyon in Skelton's *Magnyfycence":
Huffa huffa taunderum taunderum tayne huffa huffa
[...] Rutty bully, ioly rutterkyn, heyda!
—an obvious antecedent of Cab Calloway's Minnie the Moocher, who sang:
hidee-hidee-hidee-hidee-hidee-hidee-hi
hodee-hodee-hodee-hodee-hodee-hodee-ho
scoodley-woo-scoodley-woo-scoodley-woodley-woodley-woo
zit-dit-dit-dit-dittle-but-dut-duttleoo-skit-dit-skittle-but-dit-zoy
By the end of the century the word is pronounced 'hayday'. It has also acquired a nominal sense: the high spirits (especially erotic high spirits) which move someone to cry "Heyda!" For instance, Hamlet reproaches his mother's unseemly sexuality thus:
You cannot call it love, for at your age
The hey-day in the blood is tame, it's humble,
And waits upon the judgment.
And Ford writes (1633):
Must your hot itch and pleurisy of lust
The heyday of your luxury be fed
Up to a surfeit?
Something very similar happened in the last century to the old interjection "hoppla" or "whoopee", which evolved into "making whoopee".
This nominal sense seems to have died out of colloquial use in the 18th century, to the extent that the last syllable was no longer understood and was taken to have something to do with "day"; consequently (and perhaps under the influence of Shakespeare's line) a sort of reverse folk-etymology shifted the sense of the noun to
"the stage or period when excited feeling is at its height [...] the most flourishing or exalted time" (OED)
which is the sense it bears today.
Best Answer
As a transitive verb, move can mean to find a buyer for (merchandise); to sell a stock of; to cause to be sold (OED). It is first recorded in that sense in 1900. It’s not a big step from there to selling stolen or other illicit goods. The UK’s newspaper ‘The Observer’ reported in 1993 that a mutual acquaintance . . . was a key link in the network attempting to move the stolen bonds. In British English, the verb shift can be similarly used.