There is a huge 'Christian' evangelistic movement in Nigeria, with massive meetings in stadia. Tons of money can be (and is) made. They prey on superstition and fear of 'possession by the devil' causing terrified adherents to pay for quite violent exorcisms. If they don't subscribe, they risk being excluded/persecuted by their neighbours. Some of the wealthiest Nigerian 'ministers' drive around in luxurious new cars and are actually expected to look opulent.
I'm not by any means saying that Billy Graham worked in this way, but it isn't just in the USA that these type of movements exist.