Number Fever: How Pepsi Nearly Went Pop | Cautionary Tales with Tim Harford

Pepsi twice ended up in court after promotions went disastrously wrong. Other big companies have fallen into the same trap - promising customers rewards so generous that to fulfill the promise might mean corporate bankruptcy.

Businesses and customers alike are sometimes blinded by the big numbers in such PR stunts - but it's usually the customers, not the businesses, who end up losing out.