Write a form letter: “I have the ability to predict the future. I am not allowed to directly profit from this, but I can share my good fortune with you…”
Use an upcoming event that will have either an A or B outcome. Mail thousands of letters, half recommending they bet on A, half on B. After the outcome, delete the recipients of the losing prediction from your list, and send out a new C or D prediction to those who won on A or B.
After 5 or so cycles, add “Even though I am not allowed to directly profit from my ability, you may share your good fortune with me. Please mail half of your winnings back to me.” For the next mailing, delete both the losers and the non-compliant winners from the list. Continue until there are no more winners on the shrinking list.
Do stuff to gain confidence. Then Collect where successful.
The episode is called “Mail Order Prophet”.
Its not a named scam because its not successful, its an intellectual curiosity - why doesn’t this work ? Because its too long between start and finish , and the dumb person would take advice from a trusted smarter person … who would inform that its a confidence trickster at work…
The Hitchcock story is loosely inspired by the true story of “Psychiana” scam of
1928- 1948 , run by Frank B Robinson.
It has worked as a racing tout scam. You claim to have an infallible way of picking the winner of a horse race. Give the winners away for free for three days (culling the list as indicated) and then say, “If you want tomorrow’s winner, you’ll have to pay me for the name.”
The Alfred Hitchcock Presents episode is from 1957, season 3, episode 2, “Mail Order Prophet”.
It is a “perfect prediction scam”, and similar names. See for example The Skeptic’s Dictionary and Investor Home’s “A Stock-Market Scam” with the cliché that “A further caveat for investors to consider is the question of whether past performance predicts future performance.”
It’s also used by scammy stock brokers and financial advisers; after a year or so, they end up with an insanely enthusiastic cadre of clients who are bait for the big suckers.
I have heard names for it, but can’t bring any to mind. I’m thinking Martin Gardner wrote about it.
I remember something similar back in the 70s. It was based on racing tips and they advertised on the sports pages all over the place. The offer was, that you got a free tip, and if it won you sent a fee, if it lost it cost nothing.
All they had to do was to pick races with only a few horses in. In a four horse race, they would tip each horse to 25% of their customers, thus guaranteeing a return. Many clients were happy to ignore the losers because they cost nothing, and continued to send payments for the winners in return for more tips.
When the police finally called round, the scammers flat was stuffed with thousands of pounds worth of cheques, postal orders and cash. The perps had flown the scene with an unknown amount.