Something shifted inside Amazon’s Buy Box engine sometime around late April 2026 — and third-party sellers are still scrambling to understand what hit them. Sources close to the matter say an unannounced algorithmic update to the Buy Box eligibility scoring model has quietly deprioritized mid-tier sellers with strong, but not elite, account health metrics. The alleged changes appear to weight a new composite signal — internally rumored to be called “Seller Velocity Score” — that blends trailing 90-day unit velocity, refund-to-order ratios, and inventory depth in ways that existing public documentation does not reflect.
The fallout has been swift and, for many operators, financially brutal. Sellers doing $800,000 to $3 million in annual Amazon revenue — too large to ignore the platform, too small to command direct category manager relationships — are reportedly the hardest hit. Several aggregator operators and independent brand owners who spoke with Ecommerce Times on background described Buy Box ownership rates dropping from above 85% to below 60% on core SKUs within a single billing cycle, with no policy violation notices and no actionable guidance from Seller Central.
Which Seller Segments Are Getting Squeezed the Most?
The pattern emerging from seller forums, agency Slack channels, and aggregator back-channels points to a specific victim profile. Sources describe sellers with the following characteristics as disproportionately affected:
- FBA-primary accounts with SKU counts between 50 and 400 ASINs
- Categories including home goods, pet supplies, kitchen, and sports equipment
- Sellers carrying seasonal inventory overhangs from Q1 2026 — flagged, allegedly, by the new velocity scoring
- Accounts that saw refund rate spikes above 4.2% during the February returns wave tied to post-holiday fulfillment delays
One aggregator operations director — who manages a portfolio of 11 brands acquired between 2021 and 2024 — told Ecommerce Times their blended Buy Box ownership rate fell from 88% to 61% across 340 ASINs in roughly three weeks. “We haven’t had a policy strike in 14 months. Our IPI score is 620. There’s nothing in the dashboard that explains this. Seller Central tickets are getting copy-paste responses,” the director said, asking not to be identified by name or company.
Is Amazon Intentionally Pressuring Sellers Toward Vine and Ads?
The timing of the alleged update is raising eyebrows among agency leaders who track Amazon’s monetization strategy closely. The Buy Box suppression, sources allege, appears to correlate with reduced organic ranking visibility — and, critically, a subsequent surge in recommended Sponsored Products spend from Amazon’s ad console. In other words: sellers losing organic Buy Box ownership are simultaneously being served higher suggested bids to recover lost impression share through paid placements.
“It’s a squeeze play, and it’s not subtle. You lose the Box organically, your PPC cost-per-click recommendation jumps 18 to 30 percent in the same category. That’s not coincidence — that’s monetization architecture.” — Kara Dillman, Head of Marketplace Strategy, Downstream Commerce Agency, Chicago
Downstream Commerce’s Dillman, who manages Amazon PPC for roughly 60 brands, says she’s seen average CPCs in home goods rise from $1.43 to $1.91 between March and May 2026 for accounts that simultaneously reported Buy Box deterioration. She described the dynamic as “textbook margin compression designed to pull ad dollars from sellers who have no other lever to pull.”
Amazon has not publicly commented on any algorithmic changes to Buy Box scoring in Q2 2026. A company spokesperson did not respond to a request for comment by publication time.
What Are Aggregators Doing to Respond?
The aggregator community — already under pressure from elevated interest rates and compressed EBITDA multiples that have kept acquisition activity muted through early 2026 — is treating the alleged update as a portfolio-level operational emergency. Sources at two multi-brand aggregators, speaking on background, say they’ve convened internal war rooms to audit Buy Box health across their entire ASIN catalogs.
Thrasio, which emerged from restructuring in 2024 with a leaner brand portfolio, is reportedly conducting a full velocity-score audit across its remaining 1,800-plus active ASINs, according to one source with knowledge of internal operations. Perch, the Boston-based aggregator, is allegedly in direct communication with its Amazon category manager contacts to seek clarification on the scoring changes — though sources say those conversations have yielded little concrete information.
“Every aggregator right now is running the same playbook: pull the Manage Inventory health report, look for ASINs with stranded or excess inventory flags, and start clearing them aggressively — even at a loss — because the hypothesis is that inventory depth signals are being penalized.” — Marcus Albright, Director of Operations, unnamed mid-market aggregator, Seattle
Albright, who oversees 220 ASINs across four categories, said his team has liquidated approximately $340,000 in excess inventory since May 1 in a defensive move to improve what they believe are the underlying signals driving the new scoring. “We don’t actually know if it’s working yet. We’re flying blind,” he added.
Are Third-Party PPC Tools Picking Up the Signal?
Amazon PPC software vendors are now reportedly racing to reverse-engineer what changed. Sources familiar with internal development roadmaps at both Perpetua and Pacvue say engineering teams have been tasked with building Buy Box ownership correlation models that overlay ad performance data with account health metrics — attempting to surface predictive indicators of suppression before it hits revenue.
Helium 10’s Market Tracker 360 team is also allegedly analyzing the pattern. Manny Coats, Helium 10’s co-founder, commented publicly in a May 28 seller community thread that his team was “seeing anomalous Buy Box rotation data that doesn’t match historical baseline patterns” and that a formal analysis was underway. Coats stopped short of attributing the shift to an intentional Amazon policy change but acknowledged the timing was “worth scrutinizing.”
Meanwhile, SellerBoard users have reportedly begun building custom dashboards to track Buy Box ownership percentage as a daily KPI — a practice that was previously considered overkill for most FBA operators but is now, apparently, table stakes.
Could This Be a Precursor to a New Seller Tier Program?
The most provocative theory circulating in agency and aggregator circles is that the Buy Box algorithm changes aren’t a bug or an isolated optimization — but rather an early infrastructure signal for a formalized seller tiering program that Amazon has reportedly been developing internally. Sources close to the matter say Amazon’s Selling Partner Services division has been prototyping a stratified seller classification system that would assign accounts to tiers based on a composite performance score, with Buy Box priority, ad credit access, and account manager availability all tied to tier placement.
The unconfirmed program has been described, by one source who claims to have seen internal documentation, as resembling a structure similar to Walmart Marketplace’s “Pro Seller Badge” program — but significantly more granular, with reportedly five distinct performance tiers rather than Walmart’s binary badge system.
“If what we’re hearing is accurate, this is the most consequential structural change to the third-party seller experience since the introduction of FBA itself. It would fundamentally alter how brands invest in the platform — and who gets to compete for organic visibility.” — Rachel Huang, Amazon Channel Lead, Envision Horizons, Los Angeles
Envision Horizons’ Huang, who advises DTC brands on Amazon channel strategy, called the alleged tiering program “a logical but dangerous evolution” for Amazon’s marketplace model — one that could accelerate the flight of mid-market brands toward Walmart Marketplace and TikTok Shop if implemented without transparent criteria.
What Should Sellers Do Right Now?
Agency leaders and aggregator operators are coalescing around a short-term response framework while the broader situation develops. The most commonly cited immediate actions include:
- Audit excess inventory aggressively: Pull the Inventory Health report weekly and target any ASIN with more than 90 days of forward coverage for liquidation or removal — even at margin sacrifice.
- Monitor Buy Box ownership daily: Use SellerBoard, DataHawk, or Helium 10’s Market Tracker to establish a daily Buy Box percentage baseline by ASIN and flag any week-over-week decline above 5 points.
- Resist the impulse to immediately increase PPC bids: Multiple agency sources warn that reflexively raising Sponsored Products bids in response to Buy Box loss may be “feeding the machine” without addressing the underlying eligibility signal.
- Check refund rate and negative feedback velocity: The alleged new scoring model reportedly weights trailing 90-day refund data heavily — sellers with spikes from Q1 returns should prioritize proactive customer outreach and product quality review.
- Document everything and escalate through brand registry channels: If you have a registered brand, escalate through Brand Registry support rather than standard Seller Central — sources report marginally better response quality through that channel.
Whether Amazon confirms, denies, or quietly reverses the alleged Buy Box scoring changes remains to be seen. What’s clear is that the seller community’s trust in algorithmic transparency — never particularly high — has taken another significant hit. And for the mid-market operators caught in the crossfire, the damage already done to May and June revenue may not be recoverable regardless of what comes next.
