I already explained it in my first comment. Your post would get exposure through the OCD account and extra posting rewards which it wouldn't have received had those curators not stumbled upon it and nominated it.

The curators put time in for finding these posts in the masses and get rewarded for it through the compilation posts.

The compilation posts make about 10-12$ per nomination, the original posts make about 10-30$ extra depending on already accumulated rewards and rank in the compilation post.