May I ask what the biggest obstacles, for you, were in the years since 2012?
It was a long and convoluted journey, heh. When I first started subbing the book to agents, the characters were in their early twenties and I was categorizing it as kinda New Adult, kinda romance/women's fiction; I got a couple of revise-and-resubmit requests and some very nice personalized rejections, but everyone ultimately passed on it. So after a year or so I shifted my focus to another novel (Mindwalker, a YA sci-fi which was itself a rewrite of a previous project) and got my agent through that. I then sent her this novel (which was at that time titled ALVIE FITZ, after the main character) and my agent said that it felt more like YA to her; she recommended that I age the characters down a few years, which I did, and made a few tweaks to the plot as well. (Ironically I've already had a few readers say it feels more like NA to them...I think it sits right on the borderline between genres).
Ultimately, I think the fact that it took so long to sell it had less to do with the book itself and more to do with me being unable to find its niche in the market. Though I think it also helps that novels about neuroatypical characters are much more common now than they were in 2012. Maybe the literary world is just more accepting of these types of stories now.
I guess the lesson is that, if you're having trouble finding a home for your novel, don't despair. The market is always changing, and something that's unsellable now may be trending in four or five years.
Thanks, everyone.