Search terms didn’t help me either. I had to look at your profile and pick out anything you posted that had anything to do with money/currency. Then I found it relatively easily. The Stamp Stampede is interesting because you have quite a few prominent people and elected officials endorsing the campaign. On another note, who could really be offended by their message to separate money and politics? They do have a guide on that site about how to effectively stamp money, since the goal is to not have stamped bills removed from circulation. They promote stamping on the edges, not covering serial numbers, etc. and say that bill readers tend to focus on the middle third of the bill, so if the reader picks up a lot of soiling there, it might reject the bill.
Sounds like simple economics to me. You want to tip a girl? All you have is a $20? Well, we can give you ten two-dollar bills, so you can give ten tips. If you want to have a really good time, next time you come, bring two twenties!