Cory Doctorow: The pool of unredeemed frequent-flier miles is the most voluminous currency in the world, worth more than the cash supply of dollars and pounds combined.
According to a new analysis by The Economist magazine, the global stock is worth more than $700bn (£370bn), more than all the US dollar bills in circulation, and streets ahead of Britain's £42bn of notes and coins...
A close look at the rules can expose unbeatable deals. A civil engineer from California, David Phillips, became known as the "pudding guy" after calculating that an offer of frequent flyer miles with food at his local supermarket yielded a remarkable return. He spent $3,000 on 12,000 Healthy Choice chocolate desserts and earned $25,000 worth of free flights, enough to pay for travel for the rest of his life.
