Walmart's biggest sale in history was made by Shaquille O'Neal. O'Neal said in an interview with HBO that he once spent $70,000 at Walmart in a single visit. When the Miami Heat traded Shaq to the Phoenix Suns, his apartment wasn't furnished, so he went to Walmart to buy all of his essentials. O'Neal's credit card was declined during checkout, and he had to tell American Express that he was indeed trying to make the purchase.