It's a hard thing to guess. There wasn't a plethora of faery books when I wrote WICKED LOVELY (although there certainly are a bunch coming now). I didn't think there was much of a place in the market for what I write. I mean there were the folklore-fiction parents like de Lint, Bull, & Gaiman. Then there was Holly Black. I figured the market wasn't that strong, so the response to WL knocked me over, yanno?
There haven't been a lot of serious literary zombie texts either, but Carrie Ryan just nailed it beautifully.
I don't know that we can predict it--or that an absence is indicative of a market that is impossible.
OTOH, I wouldn't ever suggest writing TO a market bc that often doesn't reflect our individual passion & interest. I say write to your passion bc the genuine passion (IMO) is the ingredient that a book needs. If you've done that (as it sounds like you have) & the market's at the right place, it can work. And, yanno, if it doesn't, you can shelve it & write something else. I suspect markets will circle back around.
Honestly, I think experience like that can really make a difference. I could be biased, of course, but I think it's worth mentioning. And, the having work optioned is a big plus.
In my queries, I referenced the fact that I taught university--including gender studies, folk & fairy tales, and classic lit. I wrote folklore & feminist fiction, so that was worth mentioning. There's a paragraph specifically for presenting any important traits that are a factor. Your film school & screemwriting experience, as well as experience as a pro reader, fit that.
I'm not sure abt the quote thing. (Sorry.) I know of writers whose books were sold with endorsements attached, but I think those were in the same genre/audience.
What I know is that you certainly don't
need them. There's the illusion that this is a business abt "who you know" but I knew no one. Most writers I chat with knew no one. There are a few exceptions where they had an "in" or a quote or what have you, but I firmly believe that what sells is the writing & the story (& a dash of good luck/timing/planetary alignment).
Sometimes books that are . . .umm, not particularly well written sell on concept alone. Sometimes lovely writing takes a common concept & sells it. Sometimes market hungers or (in a rare case) name backing (be it celebrity or other) sells it. It's not a predictable thing though.
So as my experience is not useful in this one, I'll say "maybe" is my best answer
Good luck. Let me know if there are more questions I can answer. I enjoy talking to new folks
