I was of the (perhaps mistaken?) opinion that many people tended to try and avoid Penguin due to it's somewhat unethical practices, including ripping-off creators like Sankey, stocking many of the products from magicfakers:
http://www.magicfakers.blogspot.com/
...etc. etc.
I think that their own video downloads were teaching other peoples effects without permission as well (I know I downloaded Oz Pearlman teaching "Penguin" Jazz Aces when I was starting out, and I'm pretty sure Peter Kane never got paid for that, can't remember whether he was actually credited though)!
I could be wrong, but that was the impression I was under!