The trick is great and my complaints to follow don't really take anything away from it overall but
the demo is misleading when he brings the coin towards the balloon and then it cuts away and he's
holding the coin against the balloon. You can do that with a bit of thought but he doesn't teach you
how (he could have or just not cut it that way in the demo).
Also the ad says the coin can
be signed - yeah, but only by the magician.