If your Amazon sales have slowed or ad performance seems to be declining despite consistent spend, you’re not alone. Many sellers are feeling the ripple effects of the COSMO 2025 algorithm, especially since the July updates that changed how visibility and ad efficiency are measured.
COSMO, Amazon’s AI model built around Common Sense Knowledge Generation, is redefining what it means to rank and convert on the platform. Unlike older A9 or A10 systems that centered on keyword frequency and recent sales history, COSMO measures context, credibility, and shopper engagement across every touchpoint.
What Changed and Why It Matters
Amazon’s COSMO updates in mid-2025 adjusted multiple variables that directly influence both organic ranking and advertising effectiveness:
● Algorithm Priorities: COSMO now blends semantic understanding (the why behind a search) with user behavior, heavily weighting signals like detail page engagement, click-through rate, and conversions.
● Performance Sensitivity: Drops in conversion rates now carry more weight, hurting not just your sales efficiency, but also how your listings perform in Amazon’s ad placements.
● Cross-Channel Validation: External traffic and engagement from credible sources are now ranking signals. Amazon’s AI sees them as proof that your product resonates beyond its own walls.
Bottom line? Sellers who rely only on keyword stuffing or heavy ad spend are getting left behind. COSMO prioritizes listings that feel authentic, credible, and contextually useful, not just technically optimized.
The Indirect Impact on Advertising Performance
One of the biggest shifts under COSMO is how organic performance now feeds directly into ad delivery.
If your listing’s engagement dip such as fewer clicks, shorter time spent on your product detail page, weaker conversion rates Amazon’s AI reads that as a drop in relevance. That means your ads start to suffer, too.
Here’s the chain reaction we’re seeing:
- Listings lose visibility as engagement slips.
- Ads underperform because keywords tied to those listings look less relevant.
- CPCs rise, ROAS drops, and budgets stretch thinner.
That downward spiral isn’t “ad fatigue.” It’s COSMO’s interconnected system doing its job and punishing weak engagement signals along the way.
How to Regain Momentum Under COSMO
To rebuild ranking strength and ad efficiency, sellers need to optimize for semantic richness, behavioral credibility, and conversion depth.
Here’s your COSMO survival plan:
● Write copy that sounds like a real human conversation – natural, varied, and intent-driven.
● Monitor and improve engagement metrics like CTR, conversion rate, and time spent on your listing.
● Drive qualified external traffic, not just volume.
● Build trust with rich, informative content and brand credibility.
● Audit often. Even a 1% drop in conversion rate can ripple into both ranking and ad loss.
The Bottom Line
COSMO marks a permanent shift from keyword-first SEO to intent-first commerce.
Success in 2025 means understanding how every piece, copy, content, imagery, and off-Amazon presence works together to influence both ranking and ad performance.
Sellers who adapt early won’t just survive the algorithm, they’ll outperform competitors who are still clinging to outdated tactics.
So, Where Do You Go From Here?
That’s where we come in.
At Marketplace Ninjas, we’ve been tracking COSMO’s July 2025 updates since day one – testing, adapting, and building strategies that keep our clients ahead of the curve. We know exactly how these algorithm shifts are impacting visibility, efficiency, and spend across categories.
If you’re not sure how COSMO is affecting your account (or how much performance you’ve already lost), we’re offering a free 15-minute COSMO Debrief.
No strings attached, just clarity on what’s happening and where to focus next.
Book your 15-minute COSMO Debrief – Let’s get your momentum (and your ROAS) back on track.
