Supermarkets are increasingly becoming testing grounds for some of the latest technology. At Walmart’s subsidiary, Sam’s Club, customers can use an app to scan and pay for items while in the grocery aisle. Last month, Walmart sued BJ’s Wholesale Club, alleging the company infringed on patents for its Scan and Go technology. As checkout tech gets more advanced, it’s getting more competitive. Marketplace’s Kimberly Adams speaks with Don Apgar, merchant practice director at Mercator Advisory Group, about innovations in the space.