The Cards Against Humanity people are selling nothingness at a comparative bargain. Could almost be one of those old zen stories:
"Give me 5 dollars and you'll get nothing."
"Ok! 5 bucks right here. Wait! Why are you walking away? Where is it?"
"Your money was always surrounded by nothing. You gave me the money and nothing remained."
At that moment, the mark was enlightened.
http://www.imdb.com/title/tt0088323/