The word’s origins date back to around 1400AD. The Old French word for costume (meaning the ‘habit’ as worn by nuns and priests in 1200 AD) also became associated with someone who regularly pays a toll or a tax (hence the word ‘customs official’) in 1325AD; when, for some inexplicable reason later switched to mean ‘buyer’.
Now that is not just interesting history – but it is important to understand that customers have always been associated with ‘habits’ – something that was worn regularly. Customs are those practices that are practiced regularly by a group of people. There is an important clue in that word; and that is that we must appreciate that a customer wants consistency and regularity. That is their base expectation.
And good customer service is therefore something that is above all consistently. Many people define good customer service as something that ‘exceeds a customer’s expectations’. That is incorrect.
Logically, no one can consistently exceed someone’s expectations because when an expectation is exceed, people raise their expectations to that new level. Good service is consistently meeting those expectations – nothing more, nothing less.
c.1200, "habitual practice," from O.Fr. costume, from V.L. *consuetumen, from L. consuetudinem, acc. of consuetudo "habit or usage," from consuetus, pp. of consuescere "accustom," from com- intens. prefix + suescere "become used to, accustom oneself," related to sui, gen. of suus "oneself," from PIE *swe- "oneself" (see idiom). Replaced O.E. þeaw. Sense of a "regular" toll or tax on goods is c.1325. Customer (14c.) meant "customs official" before meaning switched to "buyer" (first attested 1409). Customary is from 1523.