My bank offered me a £20 reward, on one condition...

"Like most people, I never bother to read the deluge of bank marketing material that lands on my mat on a near-daily basis. But for some reason, on Saturday, I cautiously opened one letter. It was from Nationwide, with whom I have a credit card. At first glance, I was pleased. The letter stated my account had been credited with £20 - cold, hard cash I could view on my statement. Then came the surprise: In order to keep it, I "simply" had to spend at least £1,000 on new purchases between 1 May and 30 June. "If you meet these criteria, the £20 credit is yours to keep," the letter ...