Yea I used to work at a magic shop where that was one of the main products we pitched. I know you think that there is a lot of money to be made there, and it does make a decent amount. But not as much as you would think. A lot of ppl come into the shop just to see magic and not buy anything. WHen people see a Svengali trick they think, "Thats cool. I want to see some other magic." Not "Thats cool, I want to be able to do that."