> Also my favorite gimmick of all time, another now-closed loophole, was someone who realized the US Mint will sell you dollar coins at face value, with free sh

> Also my favorite gimmick of all time, another now-closed loophole, was someone who realized the US Mint will sell you dollar coins at face value, with free shipping for orders over a certain amount. So buy, say, $X worth of dollar coins for $X with free shipping, charge to your airline-affiliated credit card, go deposit them in your bank and immediately pay off the card. For the cost of the time you spent placing the order and going to the bank, you get X frequent-flier miles. This is genius. It also helps the economy. Banks hate putting small value cash into circulation - a $1 note for example 'costs' a bank the same amount to stock in a cashier desk as a $20 note in terms of space and time needed, leading to much complexity from central banks of how to get money into circulation. Coins have a pretty good amount of time in circulation, notes of low denominations don't, don't know about dollars (probably with a long tail as used as currency in many developing economies) but a £5 note has an average circulation lifetime of around 3 months before it is too crumpled, water stained, and plain worn out.