The world’s biggest retailer, Walmart, has decided that a key way to fuel its own growth is to help small businesses get bigger. The mass merchant recently announced ways it’s expanding the scope and services of its Walmart Marketplace, which allows third-party sellers to connect with Walmart’s millions of online customers. Walmart is ramping up efforts to recruit new sellers to its online marketplace after seeing how earlier efforts to expand the platform have driven sales gains for Walmart. The retailer has enjoyed strong e-commerce growth this year. Its online sales rose 27% in Walmart’s fiscal first quarter and 24% in the fiscal second quarter, outpacing competitors. The number of customers buying items on Walmart’s Marketplace was up 14% in the second quarter of this year, the company reported. Adding third-party sellers to its e-commerce platform enabled Walmart to increase the number of items it sells online to more than 400 million.