Some hayday youtubers are endorsed by hayday, they spread hayday update information before official game update, when you enter contet creator code and spend real money in hayday (example:buy cash, full farm pass), hayday developers pay the content creator cash.
However, I don't spend real money in games and I don't like the content creators, so it is useless for me.
https://www.facebook.com/watch/?v=212213553929405