Job applicants wait their turn at an Amazon center Chattanooga, Tenn. Amazon held nationwide job fairs Wednesday to fill thousands of positions as the company sees a surge in growth.

FALL RIVER, Mass. — Hundreds of people showed up Wednesday for a chance to pack and ship products to Amazon customers, as the e-commerce company held a giant job fair at nearly a dozen U.S. warehouses.

Though it’s common for Amazon to ramp up its shipping center staff in August to prepare for holiday shopping, the magnitude of the hiring spree underscores Amazon’s growth when traditional retailers are closing stores — and blaming Amazon for a shift to buying goods online.

Amazon planned to hire thousands of people on the spot. Nearly 40,000 of the 50,000 packing, sorting and shipping jobs at Amazon will be full time. Most of them will count toward Amazon’s previously announced goal of adding 100,000 full-time workers by the middle of next year.

The bad news is that more people are likely to lose jobs in stores than get jobs in warehouses, said Anthony Carnevale, director of Georgetown University’s Center on Education and the Workforce.

On the flip side, Amazon’s warehouse jobs provide “competitive” wages and could help build skills.

“They’re serious entry-level jobs for a lot of young people, even those who are still making their way through school,” Carnevale said.

The company is advertising starting wages that range from $11.50 an hour in Chattanooga, Tenn., to $13.75 an hour in Kent, Wash., near Amazon’s Seattle headquarters.