Azhidahak,

What i think Okta Viando is trying to say, and what i know from experience, is that you don't actually have to have a full stadium to gain the 5% possession. You just have to have your ticket sales set to the right price. I have a world class stadium with capacity of 206K, I only fill it to 106K, but because i dont skyrocket my ticket prices i still get 5% possession bonus.