Walmart reported a sales lift in the most recent quarter, but its actual physical stores didn't provide much of the gain.

Increasingly that lift comes instead from e-commerce, membership and advertising sales, not its core big-box base, a marked transition for the Bentonville, Ark.-based retailer that still earns the bulk of its sales and profits from sprawling supercenters.

On Thursday, Walmart said U.S. comparable sales, those from store and digital channels operating for the last 12 months, rose 2.6%. That is the smallest quarterly increase the retailer has reported in years. The number was hurt by new pharmacy pricing regulations, without which Walmart would have had a 3.4% lift, the company said. That is below analysts' estimates of a 3.8% gain, according to FactSet.

But much of the growth came from a 24% increase in U.S. e-commerce sales, a figure that includes Walmart's increasingly prominent advertising-revenue business. Walmart sells ads that run in its digital channels and stores.

"The relevance of store comps, I think, is not as pertinent as it was a decade ago," said Walmart Chief Financial Officer John David Rainey. For example, items ordered online and picked up in store parking lots are counted as e-commerce sales, he said, so increasingly stores are a digital-fulfillment node and enable speedy delivery. "It's a legacy fixation," he said. "We are not the Walmart of a decade ago."

Top executives are discussing if they should report those store-fulfilled sales differently to better reflect Walmart's current business model, he said. E-commerce accounts for nearly a quarter of overall sales.

Sales of groceries, toys, fashion and private brands were strong in the most recent quarter, and Walmart said it is gaining market share broadly, but especially among higher-income households, a term the retailer uses to describe households that earn $100,000 a year or above. Lower-income shoppers continue to spend cautiously, but they are spending, said Rainey. "It appears there were choices between necessities within the quarter because of where gas prices are," he said.

The sales lift was enough for Walmart to raise its net sales and operating-income estimates for the full year. It now expects net sales to increase 4% to 5% for the full year, up from a previous estimate of 3.5% to 4.5%. Operating income will rise 7% to 8.5% for the full year, up from a 6% to 8% range set earlier this year, the company said.

Net sales rose 5.9% to $186.1 billion in the most recent quarter ended July 31. Net income fell 9.4% to $6.37 billion as the decline of some equity investments ate into profits.