Supposedly, scientology grew out of a conversation involving Hubbard, Heinlein, and another SF writer I don't recall. Hubbard's thesis was that writing for a penny a word was no way to get rich; if you were serious about it, you'd start a religion. Which Hubbard proceeded to do ... and also write massive tomes, as though he was still getting paid a penny a word.
Yes, I’ve heard the versions of the story that had either Isaac Asimov or Arthur C. Clarke at the table when Hubbard said the way to get rich was by starting a religion.