There’s a lot that’s subjective in the business of being a writer.
That’s why it takes so long (usually) to find an agent in traditional publishing. You need the right timing and the right person to find your book, which can be difficult to line up. Nobody really knows a fast secret to getting an agent’s attention besides doing your research and presenting the best book possible.
Likewise, to reach the right readers, you need the right audience and the right timing. You should know who you are writing for and what they most like to read. I never worry about this until I’m editing (draft 3 or 4 or later) because the first couple of drafts are just for me, and what I want to read.
No matter how you release your book babies into the world, you should know that not everyone is going to love it. Also, not everyone will enjoy it in the same way. For example, I’ve read the first 13 chapters of Twilight more times than the whole book (or the other books in the series). That’s because, personally, the romantic tension and lead-up to their first kiss is the best part and I have no desire to read further since I already know what happens after that. Whenever I get an urge for some romance, sometimes I pick up my paperback of Twilight and read until I stop at the end of chapter 13. That’s just me.
Your readers will have their quirks, likes and dislikes as well. It’s not up to you to know all of them (how could you?) but keep in mind general reader desires in your genre. Always remember that personal taste changes a lot. One fan of YA dystopian novels may not necessarily like your YA dystopian for reasons that are out of your control. Just write the best book you can, and when the right readers come along, they’ll truly enjoy your story for what it is