1. It's gonna take a while for you to get your "cash prize."
2. Size is all an illusion!

3. Seriously. It really is an illusion.

4. When you "win," you actually "lose." (Money, that is.)
5. There is a market for reselling your prizes!

6. Filming for a week's worth of shows happens in a day.
7. You are escorted everywhere when you're not filming.
8. The "surprise" contestants know what they're getting into.

9. You shouldn't always trust the audience.

10. Don't expect to take a prop home from the show.

11. Phoning a friend is a really big hassle.
All facts (sans #9) provided by actual contestants.