Why Amazon Keeps Tilting Toward Third-Party Sellers — and What It Means for You

For years, the headline number has crept in one direction: the majority of units sold on Amazon now come from third-party sellers, not from Amazon's own retail arm, and that share has kept rising. If you're a 3P seller, that's easy to read as good news and leave it there. But the shift is deliberate, and understanding *why* Amazon favors the marketplace model tells you a lot about the rules you're actually playing under — and where the leverage is. This isn't a trend to cheer from the sidelines; it's a structural change you can position around.

Why Amazon prefers the marketplace model

From Amazon's seat, third-party sellers are a remarkably efficient way to grow. The seller carries the inventory risk, funds the working capital, and owns the product selection, while Amazon collects fees on the transaction and, increasingly, on the services wrapped around it — fulfillment, advertising, and storage. It's a model that scales the catalog without Amazon having to buy and own every item. The platform gets near-infinite selection, the sellers compete to drive price and availability, and Amazon monetizes the whole thing through commissions and value-added services. Once you see it that way, a lot of platform behavior stops looking random and starts looking like a system optimized to keep that engine running.

What the shift actually changes for you

The tilt toward 3P has concrete consequences for how you operate, beyond the feel-good stat:

• You're competing on a fee-funded platform. Amazon's revenue increasingly comes from seller fees and services, which means the cost of doing business — referral, fulfillment, storage, ads — trends up over time, not down. Your margin discipline has to keep pace.
• Services are the new profit center. Advertising and fulfillment aren't optional extras anymore; they're how Amazon makes money on you, which is why visibility and the buy box increasingly cost money rather than coming free with a good listing.
• Selection is your job, not Amazon's. The platform wins when sellers bring the right products. That means product research and sourcing — the parts Amazon offloaded onto you — are exactly where your competitive edge lives.
• The rules favor operators who measure. A fee-driven model rewards sellers who know their real numbers and punishes those who don't, because the costs are designed to quietly absorb margin from anyone not watching.

How to turn the trend to your advantage

The same forces that make the 3P model relentless also create the opening. Because Amazon has handed sellers the selection problem, the sellers who pick products well — and price and source them with clear eyes on the fee structure — capture outsized value. The platform's appetite for more selection is your invitation to find profitable niches faster than the next seller. The key is to treat Amazon's fees not as an annoyance but as the central variable in every decision: which products to add, how to price them, when a SKU has quietly slipped below water as fees crept up. Sellers who internalize that they're operating *inside* a fee machine — and run their P&L accordingly — are the ones who compound. Those who chase revenue and assume the profit follows are feeding the machine.

The same logic is playing out on Walmart

Amazon isn't alone in this. Walmart has been aggressively building out its third-party marketplace and the fulfillment and advertising services that ride alongside it, for the same reasons: sellers scale selection without the platform carrying the risk, and the services become a profit center. For you, that means the discipline you build for Amazon — knowing your true net margin under each platform's specific fee load — transfers directly as you weigh a second channel. The marketplaces are converging on the same model, so the seller skill that matters most is the same on both: reading your real per-unit economics and acting on them before the fees do the deciding for you.

Frequently asked questions

Is the shift toward 3P good or bad for sellers?

Both, depending on how you operate. It means more opportunity and selection control, but also a platform engineered to monetize you through ever-present fees and services. Sellers who manage margin tightly benefit from the openness; sellers who don't get ground down by the rising cost of doing business.

Does Amazon still compete with its own sellers?

Amazon still sells first-party in many categories, so you can find yourself competing against the platform itself on some products. The broad trend, though, is toward leaning on third-party selection, which is why understanding the model — and picking products where you're not going head-to-head with Amazon's own retail — is part of the strategy.

How do rising fees change which products I should sell?

They push you toward products with enough margin headroom to absorb fee increases and the cost of ads and fulfillment without going upside-down. Thin-margin SKUs that look fine today can slip below break-even as fees creep up, so the durable choices are products whose net margin survives a fee structure that trends in one direction over time.