BENTONVILLE, Ark. — Marc Lore, who helped spearhead Walmart’s transformation into an omnichannel retailer, is leaving the company on January 31. He will continue to serve Walmart as a strategic advisor until September, the company said.

In a company email, Walmart president and chief executive officer Doug McMillon credited Lore with helping accelerate Walmart’s e-commerce growth and preparing the company to handle this year’s surge in online shopping.

“Marc’s leadership helped ensure we were positioned to respond to the demand driven by the pandemic this year,” McMillon said in the email. “All of this progress is the result of good work from a lot of people, of course, but Marc’s expertise and aggressiveness have been game changing. We have learned a lot from him. I have personally learned a lot from him.”

Lore joined Walmart in September 2016, when Walmart acquired his company Jet.com for $3.3 billion. That acquisition was seen as a potential game changer in Walmart’s efforts to build scale in e-commerce and better compete with Amazon.com. Jet.com, which Lore had founded and led as CEO before Walmart acquired the business, had a unique business model that sought to let consumers save money by ordering in a way that improved the underlying economics of the transaction. Shoppers on Jet.com could save money by purchasing more than one item that could be shipped in the same package from the same distribution center.

Walmart continued to operate Jet.com as a stand-alone business for a time, but industry observers say the real prize in the acquisition was Lore and his team.

During Lore’s tenure as president and CEO of Walmart U.S. eCommerce, the company has made great strides on a number of fronts, including leveraging its physical stores as pickup sites and distribution centers for online orders. The retailer also launched its Walmart+ membership service in August to compete with Amazon Prime. Walmart was recently honored as MMR’s Omnichannel Retailer of the Year for 2020.

McMillon emphasized the importance of e-commerce to Walmart in his remarks to analysts in the retailer’s third quarter conference call.

“With the outbreak of COVID-19, the retail world clicked to a fast-forward, and our ability to adapt quickly has been crucial,” McMillon said. “Changes in customer behavior have accelerated the shift to e-commerce and digital. We were well positioned to catch and ride these waves, given our previous work and investments. Our e-commerce and omnichannel penetration continued to rise, accelerating trends by two to three years in some cases. We’re convinced that most of the behavior change will persist beyond the pandemic, and that our combination of strong stores and emerging digital capabilities will be a winning formula. Customers will want to be served in a variety of ways, and we’re positioned to save them money, provide the variety of product choices they’re looking for and deliver the experience they choose in the moment.”

E-commerce sales grew 79% in the third quarter, and Walmart chief financial officer and executive vice president Brett Biggs said that Walmart.com traffic “has been robust, with solid increases in repeat rates and good momentum in marketplace sales which grew in triple digits.”

Not everything Walmart tried in building its e-commerce business under Lore worked, the executive himself acknowledged in a recent interview on CNBC.

“We tried a lot of things,” he said. “We innovated. Not all of them are going to work. We learned from our failures.”

Prior to founding Jet.com, Lore was the cofounder and CEO of Quidsi, the parent company of the family of e-commerce websites that included Diapers.com, Soap.com and Wag.com. The company was founded in 2005 and sold to Amazon in 2011 for $550 million. Marc was also the cofounder and CEO of The Pit Inc., an internet market-making collectible company constructed as an alternative to eBay. The Pit was sold to the Topps Company in 2001.

On his Linkedin page, Lore wrote that he will be taking some time off, and plans to continue working with startups. Of his departure from Walmart, he wrote: “Reflecting on the past few years with so much pride — Walmart changed my life, and the work we did together will keep changing the lives of customers for years to come. It has been an honor to be a part of the Walmart family, and I look forward to providing advice and ideas in the future.”

Following his departure, Lore’s team will report to Walmart U.S. CEO John Furner. Walmart last year merged much of its e-commerce and physical store operations into unified teams overseen by Furner.