The integrity of the system is maintained through the use of random audits or RFID. The Walmart-owned warehouse club, Sam's Club, allows customers to download an app and scan items into their cart using a mobile application.[14] In summer 2018, Walmart China launched its Wechat-based "Scan and Go" program, allowing customers to scan items into their carts without downloading another mobile app, while paying through Wechat Payment or Alipay. The "Scan and Go"program carried 30% of all payments made in Chinese stores, and even improved sales in certain markets by 10%.[15]