A man loads groceries at the Wal-Mart Neighborhood Market in Dallas.
 
Associated Press
Wal-Mart Stores Inc. closed about 150 U.S. stores this month, due in part to rising competition from online retailers. The largest of those Web rivals, Amazon.com Inc., is reaping benefit thanks to some eager resellers.
Deep discounts at Walmart locations drew shoppers like 22-year-old Keith Yaple, who says he bought about $12,000 in discounted merchandise at one store in Hartland, Mich., so he could resell them for a profit on Amazon.
The practice is known as retail arbitrage. Thousands of sellers scour store shelves with the aim of scoring narrow margins by peddling their purchases online. Many rely on mobile applications that calculate the profits, after shipping and other fees, that they can expect to make per item on Amazon, based on recent online prices.
And for some, it’s a big business with millions of dollars in sales, using their own warehouses and staff to process the goods.
Sam Cohen, owner of e-commerce company DWNY LLC in Ocean, N.J., sent three employees in a 26-foot truck to the nearest closing Walmart, about 160 miles south, in Baltimore. They hauled off $35,000 in merchandise, like Legos and Star Wars pajamas, which he said he expects to sell for as much as $100,000 on Amazon. “It took six hours to scan and pay for all the items,” he said. “It was time well spent.”
Wal-Mart’s store closings presented a special bonanza. Earlier this month, the Bentonville, Ark.-based retailer began slashing prices by 50% in an effort to clear inventory before closing Supercenter and smaller Express stores. It eventually cut prices by 75%.
Mr. Yaple spent about three hours at the Walmart store last week buying anything he thought he could sell for close to their original nondiscounted price on Amazon, including tablet computers and security cameras.
With the help of his mother, brother and a friend—all of whom brought their own cars and pushed eight shopping carts through the store—Mr. Yaple rang up about $12,000 at the register.
He figures the merchandise will bring him as much as $8,000 in profit online.
“It didn’t matter to me what the products were, as long as they sell,” he said. “I cleared them out of pregnancy tests and condoms.”
He said the security cameras, which at half-off cost him $224, could reap him $130 in profit based on current prices on Amazon.
Mr. Yaple, who had a brief stint as a General Dynamics Corp. engineer before making retail arbitrage his primary business, sent nearly all of the goods he bought to Amazon. The company handles warehousing and shipping for a fee and takes a percentage of each sale.
Nathan Slamans, 23, also walked away from the Hartland Walmart Supercenter with a big haul. He fit about $10,000 worth of merchandise—which cost him $5,000—in two shopping carts. “I bought small, high-priced items like cameras so I could fit them in my car,” said Mr. Slamans, noting that ringing up his purchases took about 30 minutes.
Mr. Slamans said he expects to make at least $30 on each of the 20 Sonicare electric toothbrushes he bought at half-price.
Spokesmen for Amazon and Wal-Mart declined to comment.
Amazon has no prohibition on retail arbitrage as long as the goods are otherwise allowed to be sold on its namesake site.
Likewise, resellers’ merchandise doesn’t get any special designation.
Wal-Mart has said the store closings and about 10,000 U.S. job cuts would help contain costs. U.S. retail sales, including e-commerce, grew just 2.1% in 2015, compared with a 3.9% rise the year before, marking the weakest year for growth since 2009, according to Commerce Department data.
Other retailers are retrenching, too. Macy’s Inc. will close 36 stores this year andGap Inc. is in the process of shuttering a quarter of its North American stores.
For its part, Amazon on Thursday reported a 22% gain in sales during the fourth quarter and its largest quarterly profit in its 20-year history. The company highlighted rising sales from third-party sellers, like Mr. Yaple, which accounted for nearly half of the units of merchandise it shipped.
“I hope Wal-Mart closes more stores,” Mr. Yaple said.