End Times economics

I'm sure it has more to do with changes in technology and culture, than anything about how apocalypticism itself has changed, but still, it's curious:

The Millerites, predicting the imminent end of the world in 1843, only accepted pre-payment for their literature.

The We Can Know-ers, saying the world will end by October, give their literature away for free on the internet but do accept credit card donations.