“Ran’s thoughts are worthy of careful attention and his offerings are gifts to be appreciated.” -Michael Weber

It’s so simple and it all makes perfect sense.

Effect: A participant it taught about second sight. Clairvoyance… They try to sense, by hovering their hand over, which of two business cards has writing on the underside. They succeed. Then they try to sense what’s written. They succeed.

Then the performer demonstrates that it’s possible to get really good at this. The participant is handed the blank card (only 2 cards in play). They are instructed to write a piece of information known only to them.
The performer takes the card back with head turned away and hovers his hand over the card and then begins to reveal bits and pieces of the information written on the card.