Why Authority and UX are the New Search Benchmarks
The final weeks of 2025 brought a significant shift to how websites & brands are being assessed for SERPs.
With the December 2025 Broad Core Update (officially running from December 11 to December 29 – 18 days), Google has signalled that the era of “gaming the system” is largely over.
And this time the update wasn’t a minor tweak… it was a fundamental re-evaluation of how trust and user experience (UX) are measured.
At our agency, we’ve been monitoring the data across thousands of keywords and dozens of sectors. With this we have put together our deep dive into what happened, why it happened, and what it means for your SEO campaign in 2026.
What is a Broad Core Update?
Unlike Googles “spam updates” that target specific bad behaviours, or “reviews updates” that look at product evaluations, a Broad Core Update is a comprehensive recalibration of Google’s entire ranking engine.
Think of it like a global library reorganisation.
Google isn’t necessarily “punishing” a specific book; it is updating its criteria for which books deserve to be on the front display based on how helpful, accurate, and satisfying they are to readers today.
These updates often occur 3–4 times a year to ensure that search results keep pace with changing user expectations and the rise of AI-generated content.
1. YMYL: The Rise of "Verifiable Authority"
The Your Money or Your Life (YMYL) sectors, specifically Finance, Health, and Medical saw the highest levels of volatility during this update from both our clients and across these sectors in our research.
Google has significantly tightened its E-E-A-T (Experience, Expertise, Authoritativeness, and Trustworthiness) signals… which I personally believe was the right move, to reduce the ability for “quick wins” from non credible or even fake companies.
We are seeing a clear preference for:
Verifiable Entity Signals: Sites with real-world physical addresses, transparent business registrations, and clear citations… As below;
First-Hand Experience: Google is now rewarding content that proves the author has actually done the thing they are writing about.
Moving Beyond “Token” Bios: A generic author bio with a stock photo is no longer enough. Google is looking for a digital footprint that proves the author is a recognised expert in their field.
Like in this article… It’s not just about displaying the author, it’s being able to establish “who” is this author and are they credible to be speaking to the subject matter.
The Agency Note: If your YMYL site saw a drop, it’s likely because the “trust threshold” has been raised. It’s time to move from “writing about it” to “proving you know it.”
2. The UX "Penalty": Ad Density and Autoplay
For years, SEOs have focused on keywords while ignoring the “feel” of the page. This update changed that, and it’s the most notable in the News, Media, and Affiliate sites, which these seeing significant losses that look to strongly correlate with poor user experience.
Sites heavily penalised in this update often shared common traits:
Aggressive Ad Placement: Content buried under multiple banner ads.
Intrusive Pop-ups: Interstitials that block the user’s path to information.
Autoplay Videos: Particularly those that follow the user down the page.
Google’s “NavBoost” and other user-interaction signals have become more sensitive.
If a user clicks your result and immediately “pogo-sticks” back to Google because they can’t find the content amidst the ads, your rankings will suffer.
3. The "Middleman" Decline in Affiliate & Career Sites
We observed a common trend among Affiliate platforms and Career/Job tools: a steady 20–30% decline in visibility for those who act merely as “middlemen.”
Google is increasingly prioritising the primary source.
If an affiliate site simply summarises information found on Amazon or a brand’s own website without adding unique data, proprietary testing, or original photography, it is being devalued.
Similarly, career sites that offer generic resume templates or aggregate job listings without deep, expert-led advice are finding it harder to compete.
Final Takeaway: The Era of the "Subject Matter Brand"
The overarching theme of the December Core Update is the rewarding of Deep Topical Authority.
Google is moving away from rewarding individual “optimised pages” and toward rewarding brands that dominate a niche through:
Verifiable Authority: Real credentials and transparent sourcing.
Clean UX: A friction-free environment where content is the priority.
Unique Value: Providing insights that an AI or a content scraper cannot replicate.
