This all thing with promoted section it's only in rich people favour! The problem is what you are doing if you send to @null $100 to promote your post and after 10 minutes you have to change your main tag. Do you pay​ for a 10 minutes service? We all know that if you have to change your main tag, you have to make another post and delete the previous one, but the money you send to @null will promote a deleted post.