hehe I would have to SHOW you thats the problem. But you hold the Zoom Groom in one hand and keep it moving in the same direction, from the back of the neck down to the base of the tail. Don't change direction, don't turn the Zoom Groom around in your hands.
Just do this continuously for a bit, you will see some hair sticking to the Zoom Groom and some kind of gathering in a messy clump at the base of the tail where the stroke ends. right now you will be thinking, "this SO doesn't work!" and want to give up, but just keep going and finally one stroke will grab all the hair and it will clump up on the Zoom Groom, then you continue the same way but now everything sticks to the Zoom Groom, or rather, it sticks to the hair already on the Zoom Groom. DO NOT pull off the clumps that gather on the Zoom Groom (like you would be cleaning out a regular brush) DON'T do that. Just keep going. Eventually the clump will get really big and fall off, then you start again.
Does that make any sense? It is hard to explain without showing.