It appears that a lot of YA books involve love. A young girl sees a boy at school and instantly feels a connection. Sometimes they hate the boy; sometimes they are immediately attractive to one another. Invariably that boy or girl harbor a deep dark secret that threatens their budding love. They undergo challenges that bring them together and in the end fall madly in love.
While I know this is not the main story line of every book, it seems to be a common thread in a lot of them, at least the ones I have picked up lately.
This is my question. Can you have a YA book where the relationship starts as a friendship and builds over time to something more or does the protagonist need to have an automatic attraction to someone in order for the book to sell?
What do you think? Do you need a romantic story line for a YA book to sell?