[Estragon]

There's a con based on this: send half your marks a prediction that the stock market will go up next week, and half a prediction it will go down. Repeat next week, restricting to whichever set received the correct prediction. After five weeks, you'll have a group of people who think you've accurately predicted stock market movements for five weeks in a row, and some of them will be prepared to pay for your next prediction.

[billmcneale]

I remember reading this anecdote to explain the anthropic principle:

http://beust.com/weblog/2010/08/17/fun-with-the-anthropic-pr...

[hobbsy]

This reminds me of Derren Brown's The System: http://en.wikipedia.org/wiki/Derren_Brown#Derren_Brown:_The_...

[eridius]

Do you watch Leverage too?

(Leverage is a TV show in its 4th season, and last week's episode included this very con http://www.tv.com/leverage/the-boiler-room-job/episode/13919...)

[jonkelly]

That's really pretty neatly evil, I hadn't heard of that.