I'm talking about THIS effect specifically not marketed tricks in general. Plus I didn't even know that the trick had been released until someone posted the link here. Finally why in the world are you getting all defensive considering you yourself are doing the same thing:
Go buy it now that you know it's being sold.
As far as I know, they don't sell them. I just make mine.
Like mentioned above, I print out the picture of the Hershey Kiss (on a semi-thick glossy paper, so it somewhat resembles a playing card finish) and glue it on the card (note that I use rubber cement, just because it tends to work out better for me--and I just love the stuff).
Also note that you can use other stuff besides a Hershey Kiss. It's such a simple concept, but it's so strong, and it's adaptable to other things (although you'd have to come up with other patter...no more sealing it with a kiss, heh). Try and come up with some other things to make appear and "pop off" of a card; it's fun and rewarding.
Go buy it now that you know it's being sold.