Costumers pay the bill in a tax-free shop in Sanya, south China's Hainan Province, May 1, 2011. The offshore tax-free scheme for mainland shoppers was formally launched across Hainan on Sunday. The average volume of shoppers who visited the tax-free shop in Sanya reached 18,000 per day since the trial of the scheme on April 20. (Xinhua/Hou Jiansen)