This is a 'bank night' routine using two envelopes (i.e. no matter which envelope your spectator chooses, they will open it up to find that they have lost). So what's the problem? You never actually open the other envelope to prove it is the winning envelope. Instead, the manuscript goes through some psychological subtleties which supposedly leave your spectator not caring that you do not show the contents of the remaining envelope. I'm not a fan of this. No matter how well it's executed, most people will demand to see that the remaining envelope contains money. The psychological subtleties are cool, but you really need to supplement this with another 'bank night' method which allows you to open the remaining envelope and reveal the money (see Richard Osterlind's Mind Mysteries, or perhaps Blank Night by John Archer).

It's OK. Should be half price or contain 3 more effects on the download.

Let me say I have done this over 100 times and never had anyone question what was in the "other" envelope. What you say and how you say it are of a great importance in this effect. What you are getting in an incredibly subtle way of using 2 envelopes to produce an effect that looks like real psychology at play. This is mischievous in its nature and is better suited using it in a routine based of subliminal or psychology based influence type tricks. I use this one daily and I give it my highest recommendation.