Websites don´t sell their ad-space directly. Usually they pass their spaces onto an advertising service (like Goodle Adworks) which can freely use it. Those ad-companies place advertisements based on the possible interest - so it´s no wonder that the buzzerbeaterDB ad appears on Buzzerbeater - it´s clearly hitting plenty tags from the Ad-Provider.
Some pages / ads might be blocked by the original site if they are found appropriate, but it´s for sure not placed there by Buzzerbeater officials.
Zwei Dinge sind unendlich, die Dummheit und das All...