Elmer Gantry 2.0
A charismatic con man declares that the world is going to end on a specific date. He calls for donations, ostensibly to alert nonbelievers of the joyful and ominous news.
The meme goes viral and all of a sudden, his normal income from donations increase 1000x. Instead of backing off, he doubles down and declares that he is going to spend \$100,000,000 buying billboards around the world.
The world doesn't end, but he disappears to a gated community in Costa Rica called "Rapture."
Coda: He is discovered, says that he's been in Heaven, and boy does he have a lot of exciting new information to share.