Idea for a novel?
An ad man realises that the quickest way to get rich is to start a religion and so teams up with a public opinion specialist to create the most appealing belief system. However, as their new religion develops, the founder starts to claim that the god they have invented is now talking to him, and the beliefs he's espousing get increasingly less orthodox. And increasingly schismatic, until the new followers rise up and martyr him. Which is when things really get going. To make a profit, you need to make a prophet.