Amazon Q1 2026: 3P seller share slips as Amazon retail accelerates

Amazon beat on revenue and operating income, with AWS up 28% and advertising revenue topping $15B. Underneath the headline, independent analysis from Canopy Management and Modern Retail highlights that 3P seller unit share slipped quarter over quarter while Amazon retail (1P) accelerated. The shift is small in any single quarter but compounds quickly when paired with Rufus-driven discovery changes.

Amazon has always sold first-party alongside its marketplace. What changed in Q1 2026 is the rate at which 1P is reclaiming unit share in categories where Amazon has a strong private label or retail vendor base. Combined with rising ad revenue, the practical effect is that 3P sellers pay more to defend the same placements they used to win organically. Whether you call it competition or consolidation, the operational answer is the same: tighter margin discipline.

Per Modern Retail, Rufus monthly active users are up 115% year over year and Amazon attributed $12B in incremental annualized sales to it on the Q1 2026 call. Rufus reshuffles discovery away from pure keyword search and toward conversational, attribute-led queries. Brands with thin or generic listings lose surface area; brands with structured attributes and clean variation families gain it.

Three things. One, run a Buy Box and unit-share audit by parent ASIN to see where 1P is taking back share. Two, reconcile per-SKU margin including all 40+ fee types so you do not spend ad budget defending unprofitable units. Three, treat Rufus as a separate discovery surface and audit attribute completeness on your top 100 ASINs. Without a clean unit-level P&L, the share shift will not show in your own data for two or three quarters.

Nova is the operating system for Amazon brands. Seller Cockpit surfaces Buy Box and unit-share trends per ASIN. Profit & Loss reconciles 40+ Amazon fee types to the cent so margin decisions are based on net contribution, not gross sales. PPC Analytics separates branded from non-branded TACoS so defensive ad spend is visible. Custom Analytics lets you build the share-tracking views your team needs without waiting on a quarterly Marketplace Pulse report.