Well the drug dealers were certainly there first, etymonline.com has this to say of "user": Of narcotics, from 1935; of computers, from 1967."
I am struggling to find a source for who first called users "users" back in 1967 - Actually I see it being used in the 1965 "Multics" papers [0] and the 1964 article in The Atlantic "Computers of Tomorrow" [1], as if it was already a term-of-art.
OED gives the following usages, the first of which suggest users predate computers:
1950 Science 112 732/1 Analog machines..are enthusiastically supported by their users.
1959 E. M. McCormick Digital Computer Primer x. 139 The number of instructions which can be executed by a computer represents a compromise between the designer's and user's requirements.
Thanks for a good reference! It makes sense that "users of a service" or "user of a machine" slipped its way into computer jargon, no need to be coined or anything.
I'm tempted to pick up a copy of Digital Computer Primer on ebay, I love the old explanations of what these machines even are.
I am struggling to find a source for who first called users "users" back in 1967 - Actually I see it being used in the 1965 "Multics" papers [0] and the 1964 article in The Atlantic "Computers of Tomorrow" [1], as if it was already a term-of-art.
[0] https://multicians.org/history.html
[1] https://www.sas.upenn.edu/~traister/greenbf.html