How large (or small) is the audiophile market?

Paul at PS Audio once did some math that arrived at a population of 250k. Obviously, your definition of the target for inclusion will vary, but for high end stuff that might be close. 

Not too many people I know indulge themselves with fine audio gear.   I don't have any co workers or friends that spend on HiFi.     I'm pretty low key about my hobbies in general but it's not hard to see I've spent some money on this stuff.    Well worth the enjoyment it get in return though without question.    

I had a marathon listening session last night in my main room.   Haven't done that in a while.  I needed to escape for a while 

A logical starting point would be 1% of the population which is 343 million(2025) in the United States and 40 million in Canada. I would include entry level products from Emotiva/JBL/Klipsch and Chi-Fi due to the fact these are still separate components. That computes to around 3.8 million potential HEA customers in North America. Given the current trend to "shame" true HEA, a vast majority of the bottom feeders will stay complacent with budget gear regardless of financial means. Possibly 25% of the 3.8 million buyers will consider upgrading which leads to around 950,000 North American potential buyers. Factor in aspirational buyers/tire kickers and the WAF and there could be around 750,000 actual HEA buyers in the North American market.

My perception mirrors @oddiofyl .

I have a single friend who actually spends money on high-end gear. I don't know anyone else who does. In high school I was the only person who had a component system. Same thing in college. Almost the same thing in dental school. I knew a couple of people who actually had a nice system. Decades later I know only one other person who cares about audio and has a high-end system.

When I am asked about hobbies or interests all I get is a blank stare after I respond "Listening to music in a dedicated listening room".

I do have a few friends who like coming over to hear my system, but they are unwilling to invest in good gear for themselves.

Definitely a lonely hobby.

It's only Rock n Roll, but I like it, like it, yes I do.

Outdated audiophile brands have always been a clueless bunch ---> no idea how to tap into the vast numbers of the world’s unidentified ’audiophiles".

For example, Sony has been selling its XM5 Bluetooth headphones like hot cakes. Any young person who bought it and said "Omg, I am hearing things in very familiar songs that i have never heard before" is a bonafide audiophile. Such a person will be able to identify tiers of improvements in sound quality, if exposed to gear and will buy it if within financial reach.

A sizable majority of the younger hometheater-ing dudes are audiophiles. But, they seem to despise the word and will never say it....probably has a lot to do with the lousy personalities who’ve propped themselves up as the face of audiophilia.