An old scam: "Send us $50, and we will use our connections to get your child admitted at the college of their choice! Guaranteed, with a full refund given in the event of a rejection!" Then the scammers do nothing, refund the portion of the money sent in by applicants who were later rejected, and keep the portion of the money sent in by applicants who were later accepted.

I saw that used as a joke on Facebook (though the actual example was “I will use sorcery to predict your expected baby's sex for $1000, and I will refund you if I'm wrong”), but I didn't think anyone had used that in real life. (But I really oughtn't be surprised this much.)