Inside Walmart's master plan to catch Amazon, using stores to entice sellers and speed up delivery

Walmart employs more people than any other company in the world and is the country's largest grocer. But when it comes to e-commerce, Amazon is the clear leader, with 39.5% of the market share compared to Walmart's 7%. Now Walmart has ambitious new plans, and new leadership, to try and catch up. CNBC got an exclusive interview with Walmart's new e-commerce chief Tom Ward to hear his plan for leveraging Walmart's 4,700 U.S. stores to entice sellers to Walmart and speed up local delivery programs.