“Rare” (meaning “uncommon”) and “rare” (meaning “undercooked”) are actually two different words that nowadays happen to have the same spelling and pronunciation. The first “rare” 1 stems from Latin “rarus” and has cognates in most Romance languages. The second “rare” 2 is of Germanic origin, and used to be written “rere”, “rear” etc in the (distant) past.
One relevant standard legal term is deponent. From Henry Black, A Dictionary of Law (1910):
DEPONENT. In practice. One who deposes (that is, testifies or makes oath in writing) to the truth of certain facts ; one who gives under oath testimony which is reduced to writing ; one who makes oath to a written statement. The party making an affidavit is generally ...
The idea of consumer loyalty is nicely captured in the McKinsey Consumer Decision Journey:
The original article was published in 2009. McKinsey published a “new consumer decision journey” in 2015, available on the same site.
Tne terms introduced by ...
John is a long-standing customer:
a person, business, or institution that has been a customer for many years.
The expression doesn’t necessarily imply loyalty to a brand but just the fact the for some reason you have been buying products of the same brand for years.
An Habitual customer does not convey the capriciousness of the choice of brand only the necessary consistency. A Hostage customer does not sound like the right part of speech. A more descriptive phrase would have more options to describe his relationship.
"He is a fan by default, or in name only."
"He is a fan based on ownership, whose and of ...
Actually workation appears to be a recent usage, though not common yet:
A workation (sometimes spelled 'workcation') is a working vacation (in the UK we might call it a 'workoliday', or a 'woliday')
A vacation that combines business and leisure.
2013, Vanessa Van Edwards, How I Make My Living on ‘Workations’, The Huffington Post- As long ...