Branded Bills to Aid the American Economy

This artist has come up with the idea of selling the rear of American dollars to advertisers, therefore generating $14 billion a year for the US economy. Here's how it works:

"The average 100 USD Note is circulating for 7.4 years, it changes hands on average 3x per week, so each ad on a 100 USD note is seen by more then 1000 persons. I would say, this can easily be sold at 5 USD/note.The other notes are much shorter in circulation:

$1: 1.8 years
$5: 1.3 years $10: 1.5 years $20: 2 years $50: 4.6 years

On average an ad on a bill might only be sold for 1 USD, however, given the fact that each day the bureau of engraving and printing produces 38 Million USD bills, this could result in 14 billion USD, more then the actual printing costs."

A very clever idea in my opinion.