This is probably because they no longer pay out for them!!
This is from the email they sent to affiliates in March 2005
QPD and TSP
************************************************** ********************
This is just a brief note to inform you that QPD and TSP will be removed from the Tradedoubler network from the 8th April 2005. Please select from one of the recommend alternatives listed below.
They may no longer be paying for those clubs, but the links are STILL in their admin area, which really frustrates me, as I have posted on here that this is the case, but alas
TD have ignored me! Ah well I guess lots of poor people like yourself will be caught out, and end up posting links that'll make them no money!! Appalling!