Something is happening inside Amazon’s marketplace machinery that a growing number of high-volume sellers are calling a deliberate squeeze — and sources close to the matter say internal discussions at Amazon have at least touched on the mechanics of how algorithmic Buy Box allocation intersects with first-party competitive interest.
Over the past 60 days, seller forums, private Slack groups, and conversations at the recent Prosper Show afterparties have lit up with variations of the same complaint: FBA sellers in beauty, home goods, and nutrition are watching their Buy Box win rates drop precipitously — in some cases from north of 90% to below 60% — without any corresponding change in price, fulfillment performance, or inventory health.
The unconfirmed theory gaining traction in operator circles? Amazon’s A10 algorithm — or whatever iteration is now live — is allegedly weighting Buy Box allocation in favor of Amazon’s own retail division and its private label brands like Amazon Basics, Solimo, and Mama Bear in categories where margin is highest.
What Are Sellers Actually Seeing in Their Data?
The pattern reportedly first surfaced in late March 2026, when a cluster of sellers using Helium 10’s Market Tracker 360 and Seller Labs Pro began noticing anomalous Buy Box suppression events that didn’t correlate with traditional loss triggers. No price gap. No IPI score dip. No customer metric degradation.
Brandon Young, the founder of Seller Systems and one of the more analytically rigorous voices in the Amazon seller community, has been vocal about the anomaly in his private coaching community.
“We’ve pulled data across forty-plus accounts in beauty and home goods, and the suppression pattern is not random. When Amazon has a competing ASIN in the same subcategory, our clients’ Buy Box win rates are falling 18 to 35 points on average over the last two months. That is not noise.” — Brandon Young, Founder, Seller Systems
Young stopped short of calling it intentional, but said the statistical clustering is “hard to explain by accident.”
Meanwhile, sources close to a large third-party aggregator — reportedly one of the top-fifteen Amazon roll-ups by portfolio GMV — say their internal analytics team flagged the same pattern in April. The aggregator, which sources say manages over 200 active ASINs across personal care and kitchen categories, allegedly escalated the issue to their Amazon strategic account manager, only to receive what one source described as “a boilerplate non-answer about algorithm confidentiality.”
Is Amazon’s Private Label Strategy Accelerating Again?
Amazon famously scaled back its private label ambitions under public antitrust scrutiny starting in 2022, reportedly culling hundreds of in-house brands. But sources inside two separate seller agencies say there are signs of a quiet re-expansion — particularly in high-margin consumable niches where Amazon can leverage its logistics cost advantage most aggressively.
Kara Larson, VP of Marketplace Strategy at Amify, told colleagues at a recent industry dinner in Seattle — details of which reached Ecommerce Times through multiple attendees — that her team has seen what she characterized as a “structural shift” in how the Buy Box is behaving for their managed accounts.
“In Q4 2025 we could predict Buy Box outcomes with about 87% accuracy using our standard pricing and fulfillment model. That predictability has deteriorated. The variables that used to govern outcomes are behaving differently, and we’re being forced to rebuild our optimization playbooks.” — Kara Larson, VP of Marketplace Strategy, Amify
Larson reportedly has not publicly attributed the shift to private label interference — noting that algorithm changes, demand signals, and fulfillment cost recalculations could all be contributing factors — but sources say the internal Amify hypothesis leans toward a competitive overlay in the ranking logic.
What Does Amazon Say — and What Are Regulators Watching?
Amazon declined to comment on specific algorithmic mechanics when reached by Ecommerce Times, providing only a statement affirming that the Buy Box is “determined by a range of factors including price, availability, fulfillment method, and seller performance metrics, applied consistently across all sellers including Amazon Retail.”
But that framing is precisely what has drawn scrutiny before. The European Commission’s Digital Markets Act enforcement team reportedly issued Amazon a supplementary information request in May 2026 — unconfirmed, but referenced by two Brussels-based trade lawyers who follow marketplace competition cases — probing whether Amazon’s self-preferencing commitments made in the 2023 DMA settlement are being honored at the algorithmic level.
In the United States, the FTC’s marketplace competition unit — still active despite leadership changes — is allegedly monitoring a dossier of seller complaints that has reportedly grown by over 40% since January, according to a source with indirect knowledge of the unit’s case pipeline.
Which Seller Categories Are Reportedly Most Affected?
Based on aggregated accounts from sellers, agency operators, and aggregator sources, the alleged suppression appears most concentrated in:
- Beauty and personal care — particularly skincare, hair care, and grooming, where Solimo and Amazon’s white-label partners compete directly
- Home goods and kitchen — especially storage, small appliances accessories, and cleaning, where Amazon Basics maintains wide SKU coverage
- Baby and toddler — where Mama Bear holds notable shelf position and margin
- Nutritional supplements — where Amazon’s private label exposure is smaller but reportedly growing
- Pet supplies — where Wag, Amazon’s pet brand, has reportedly expanded its ASIN count by roughly 30% in the past six months
Sellers in electronics accessories and industrial categories report no unusual Buy Box behavior, which some operators say is consistent with a targeted rather than systemic algorithm change.
How Are Sophisticated Sellers Responding Right Now?
The operational response in the seller community is bifurcating. Larger, more sophisticated operators are reportedly accelerating multichannel diversification — pushing harder into Walmart Marketplace and DTC Shopify stores — while mid-tier sellers are trying to game out the new Buy Box reality with more aggressive pricing strategies that sources say are margin-destructive.
Envision Horizons, one of the larger Amazon agency operators with a reportedly sizable beauty book, is said to have internally issued new Buy Box guidance to clients in late April that deprioritizes win-rate maximization and shifts focus toward contribution margin per unit — essentially conceding some Buy Box share in exchange for preserving blended account health.
“Chasing Buy Box at any cost in this environment is a trap. If the floor has shifted, you need to recalibrate what winning actually means for your P&L.” — attributed to a senior strategist at a major Amazon agency, speaking anonymously
On the tooling side, Pacvue and Perpetua are both reportedly in active development on enhanced Buy Box diagnostic layers that can flag anomalous suppression events by ASIN and cross-reference against known Amazon private label overlap. Sources at one of the two companies — who declined to be named — said the feature is “further along than we’ve publicly communicated” and could ship before Q3.
What Should Sellers Do While This Plays Out?
Operators and agency leaders who spoke with Ecommerce Times — most off the record — converged on several near-term tactical recommendations:
- Audit Buy Box win rate by ASIN against a baseline from Q4 2025, and flag any accounts showing greater than 15-point drops without price, inventory, or metric changes
- Cross-reference flagged ASINs against Amazon’s own private label catalog using tools like Helium 10’s Black Box or manual SERP audits to identify competitive overlap
- Document suppression events with timestamps and account health screenshots — both for potential escalation with Amazon and as a regulatory paper trail if third-party complaints gain traction
- Stress-test multichannel revenue by modeling what a 30% permanent Buy Box loss in core categories would do to blended unit economics, and invest in Walmart and DTC infrastructure accordingly
- Engage your Amazon SAS Core or account manager in writing, creating a documented request for explanation — sellers who have done this report marginally more substantive responses than phone inquiries
None of this is confirmed as necessary yet. Amazon has not acknowledged any policy or algorithm change. The suppression pattern, while widely discussed, has not been independently verified at scale by a neutral third party.
But the volume and specificity of the complaints — coming from operators managing hundreds of millions of dollars in annual Amazon GMV — suggests this is not mass hallucination. Something, sources say, has changed. Whether it’s intentional competitive leveraging, an AI-driven margin optimization experiment, or an unintended consequence of Amazon’s broader logistics cost rebalancing initiative, the operational impact for third-party sellers in these categories is real and reportedly worsening.
Ecommerce Times will continue monitoring this story as more seller data becomes available and as the regulatory picture clarifies. If you are a seller with documented Buy Box anomaly data in the affected categories, contact our editorial team.
