A customer shops for chickens at a Sam's Club store, a division of Wal-Mart Stores, in Bentonville, Arkansas June 4, 2009. Wal-Mart Stores Inc's Sam's Club warehouse division is improving the quality of its fresh produce and meats to lure price-conscious shoppers, even if the efforts leave it with little margin on a product. REUTERS/Jessica Rinaldi (UNITED STATES BUSINESS)