Walmart Built Its Marketplace in 2009. It Spent a Decade Pretending It Hadn't.

In 2009, while Amazon was teaching the world that a store could sell things it never owned, Walmart quietly did the same thing - it opened Walmart.com to third-party sellers.¹ Then it walked away from the door it had just unlocked. For most of the next decade the marketplace sat there, technically alive and strategically asleep. Walmart had the idea early and treated it like a hobby. That gap - between owning the option in 2009 and finally acting on it more than ten years later - is the whole story.

The official version is that Walmart boldly pivoted into e-commerce to take on Amazon. The truer version is duller and more useful: Walmart spent years building, buying, and burning credibility before it understood that the platform it already had was worth more than anything it could acquire. The reversal everyone celebrates wasn't a launch. It was a company finally taking its own neglected asset seriously.

A door left open for a decade

Launching a marketplace and committing to one are not the same act, and Walmart proved it. After opening to third parties in 2009¹, the platform drifted. Sellers were gated behind a 'Request to sell' button that asked about revenue and catalog size and then mostly said no. The supply that makes a marketplace a marketplace - millions of long-tail listings nobody at headquarters has to source - simply wasn't allowed in at scale. The trade-watchers who tracked it described Walmart as a giant that had built the foundation of a flywheel and then refused to push it. The instinct that built Walmart - control the shelf, vet the supplier, own the relationship - was exactly the instinct that throttled the marketplace it now needed.

So Walmart tried to buy its way past its own hesitation. In August 2016 it agreed to acquire Jet.com for $3.3 billion - $3 billion in cash plus up to $300 million in stock paid out over time - and the prize wasn't a delivery network. It was a person. Marc Lore became head of Walmart's U.S. eCommerce upon close, having agreed to stay five years.² The deal bought leadership and digital credibility, not infrastructure; Jet.com the product was wound down within four years, discontinued in May 2020.¹¹ A $3.3 billion acquisition that was really a very expensive hire tells you how short Walmart felt on conviction - it would rather purchase belief than build it.

Lore retired in early 2021, at or near the five-year mark he'd agreed to as part of the acquisition.² By then the borrowed belief had done its work, and Walmart's real reversal was about to begin in earnest: not a louder copy of Amazon, but a different machine built on a foundation Amazon couldn't replicate.

The weapon was the stores all along

Here is the turn that made the marketplace finally matter. Walmart Fulfillment Services arrived in February 2020 - eleven years after the marketplace itself - giving third-party sellers an Amazon-FBA-style 'store it, we ship it' option.⁹ That late arrival was the structural disadvantage trade analysts had flagged for years: Amazon's invisible marketplace ran on FBA, and Walmart had no equivalent for a decade. But Walmart had something Amazon spent billions trying to build from scratch - thousands of supercenters within driving distance of most of the country. Store-fulfilled pickup and delivery turned those buildings into the last mile, and Walmart's own FY2025 filing names that combination - store-fulfilled pickup and delivery, plus marketplace - as what drove its double-digit ecommerce growth on $674.5 billion of total net sales.⁴ Amazon built warehouses to get close to customers. Walmart was already there, and finally noticed.

Then came the second half of the machine, and it's the part that turns a low-margin marketplace into a real business. More sellers mean more products, more products mean more searches, and a crowded search page is the most valuable advertising inventory in retail. Walmart Connect, the ad business, monetizes exactly that attention. In the first quarter of fiscal 2025, global ecommerce grew 21% while Walmart Connect grew 26% - and Walmart's own filing draws the line directly, noting that marketplace sellers drove the growth in advertiser counts.⁵ The third-party seller doesn't just pay a take rate on the sale. He pays again to be seen. The goods on the shelf buy the shelf.

With the fulfillment moat and the ad engine in place, Walmart finally pushed the seller floodgate it had held shut for thirteen years. In August 2022 it replaced the gated 'Request to sell' button with an open 'Join Marketplace' flow, almost entirely removing pre-approval - and nearly 1,000 new sellers a day poured in that week.⁶ The result is a step-change in scale: Walmart Marketplace crossed 200,000 active sellers for the first time by mid-2025, adding 44,000 in five months against 59,000 for all of 2024 - a 30% jump in seller count in less than half a year.⁸ The company that spent a decade saying no to sellers had built the machinery to say yes at scale, and the supply came rushing through the door it had finally unlocked.

Didn't opening the floodgates invite the rot?

The honest objection is that Walmart didn't win a strategy debate so much as surrender a quality standard. The same open onboarding that brought a thousand sellers a day also stripped out the vetting Walmart once prided itself on. A September 2025 CNBC investigation found that Walmart had made seller and product vetting 'more lax in a bid to compete with Amazon,' uncovering sellers impersonating legitimate businesses and counterfeit health and beauty products on the platform.⁷ That is real, and it's the price of the model: an open marketplace is a leverage machine that scales the bad listings as efficiently as the good ones. But notice what the criticism concedes - Walmart only has a counterfeit problem because it finally has a marketplace worth flooding. The risk is the proof. A dormant platform has no fakes because it has no sellers; the rot is what scale looks like before the controls catch up. The strategic question isn't whether the floodgates let in trouble - they did - it's whether Walmart polices it fast enough to keep the trust that makes the ad engine worth anything.

Walmart didn't embrace the marketplace it once resisted. It embraced the marketplace it once ignored - and the distinction is the lesson. The idea was never the hard part; Walmart had it in 2009, a year when Amazon was already demonstrating the power of the model. What took a decade was conviction: the willingness to open the gate, the patience to turn stores into shipping docks, and the nerve to stack an ad business on goods it didn't own. The flywheel was always sitting there. Walmart just spent ten years refusing to give it the first push - and then discovered the push was the only part that ever mattered.