I have never been good at affiliate so I honestly don't have a full idea about how numbers should be
but my friend I guess you should consider how much betfury gives back for their players in term of cashback-rakeback-races-dividends....etc
I think Betfury ( and other dividends casinos ) can't be compared with other casinos since their revenue isn't the same

about the cashback thing , you sure it happened in last June ? cause it's been like this for over a year and yeah it was a sudden change if I remember right