I cut my teeth on fantasy and science fiction from 1976 to 1984. Those were my heavy reading years. In 1984, I went to college and my pleasure reading plummeted.
What does this mean?
Well, that means that the library carried books already published in previous years, so my early reading hit the years 1968-1977. That's significant because those are the final years before media fandom broke out. There were some media books out there, like the Star Trek books or a few Star Wars books, but nothing compared to the flood that is now. The vast influence of books consumed by me were from authors that existed before the big media boom.
That makes me, I think, is one of the last of the young old-timers, if that makes any sense. My sense of what a book should look like and how it should unfold is now archaic. If you dropped what I write back into the late 70's to early 80's, I'd probably do perfectly well. That is, I'd fit in with the times.
When I look at the fantasy charts, all of them, I don't see where my books would fit, nor nothing like them in the in the top 100's. The only place that comes close is "classics", but I certainly don't fit there, and even then I think I'd be a bit of an odd duck.
So who the hell is my audience? I don't know. There's marketing problem #2.