Do Backlinks Still Matter? What 27,000+ Domains Reveal About Ranking in Traditional Search and AI Overviews

Google’s AI Overviews (AIO) are changing how users see and interact with search results. For years, backlinks and domain authority have been the backbone of SEO strategy—but do they still matter when Google’s AI is generating the answer on top of the SERP?

MonitLabs set out to answer this with data, not opinions. Their three-part ranking factors study analyzed more than 27,000 domains and 24,000+ keywords to understand how backlinks and authority metrics correlate with visibility in both traditional search results and AI Overviews.

The findings confirm that backlinks still help—but they matter very differently depending on:

• Whether you’re targeting traditional SERPs or AI Overviews
• Whether your keywords are informational or commercial
• How authoritative your domain already is
• Which industry you operate in

Below is a breakdown of what the study found and how to apply it to your SEO strategy.

Study Overview: Scope and Methodology

MonitLabs’ research was conducted between November 3–7, 2025, and covered a wide competitive landscape:

27,204 domains across 11 industries for informational queries:

11,000 informational keywords (1,000 per industry), all phrased as questions

13,000 commercial keywords across 13 industries, focused on product and service queries

41,389 domains included in the commercial intent analysis

Signals Measured

The study tracked three core authority-related signals:

These were correlated against three visibility outcomes:

1. Top 10 SERP appearances (classic organic results)
2. Presence in AI Overviews (whether a domain/URL appears in AIO answers)
3. Position-weighted SERP Score (10 points for rank 1 down to 1 point for rank 10)

Correlation Methods

To understand how strongly these signals relate to visibility, MonitLabs used:

Using both provides a more realistic view of how backlinks and authority behave in the wild.

Finding #1: Backlinks Still Help in Traditional SERPs—but Only Modestly

For classic organic rankings, the study confirms what most SEOs expect: backlinks and authority correlate positively with visibility.

However, the strength of that correlation is weaker than many assume.

Informational Keywords (Traditional SERPs)

For informational queries:

A Spearman correlation of 0.22 indicates a real but limited relationship. Backlinks and authority help, but they explain only a slice of why certain pages rank.

Implication:

• Backlinks and authority are still important ranking factors in traditional SERPs.
• They are not the dominant or sole drivers of rankings.
• Content quality, topical relevance, intent match, UX, and other signals clearly play a major role.

Finding #2: Backlinks Play a Much Weaker Role in AI Overviews

When the focus shifts from classic SERPs to AI Overviews, the relationship between backlinks and visibility changes dramatically.

Informational Keywords (AI Overviews)

For informational queries in AIO:

This suggests that AI Overviews are not heavily dependent on traditional link-based authority signals, especially for informational questions.

Instead, AIO likely emphasizes:

• How directly and clearly content answers the query
• Topical coverage and depth
• Relevance to the specific question
• Possibly structured information and clarity

Implication:

• A strong backlink profile that works well for classic rankings does not guarantee inclusion in AI Overviews.
• For AIO, answer quality and relevance appear to matter more than raw authority metrics.

Finding #3: Commercial Keywords Behave Differently

The study reveals a clear split between informational and commercial queries.

Commercial Keywords (AI Overviews and SERPs)

For commercial queries:

• Backlink-to-AIO correlation (Pearson): around 0.08
• Still modest, but roughly double the informational keyword correlation
• For traditional SERPs, backlinks also showed stronger positive correlations than in the informational set (though still not overwhelming).

MonitLabs suggests a plausible explanation:

• Large, authoritative sites often underinvest in long-tail informational content.
• They may focus more on commercial pages (product, category, service pages) where their strong backlink profiles and brand authority are more directly leveraged.
• As a result, for informational questions, many big brands simply don’t have the best or most comprehensive answers, reducing their AIO presence.

Finding #4: High-Authority Domains See Sharply Diminishing Returns

Perhaps the most practically useful finding from Part 1 of the study was the diminishing returns pattern among high-authority domains. For domains with an authority score of 70 or above:

• The Spearman correlation between domain authority and SERP occurrences dropped 91% (from 0.22 to just 0.019)
• URL authority correlation dropped approximately 49%

In other words, once you’ve reached a high level of domain authority, pumping more resources into backlink acquisition provides dramatically less incremental benefit for traditional search visibility. For AI Overviews, the effect was even more stark — correlations hovered near zero or went slightly negative for high-authority domains.

This finding should directly inform how established brands allocate their SEO budgets. Beyond a certain authority threshold, investing in content depth, topical coverage, and user experience may yield far better returns than additional link building.

Finding #5: Industry Context Changes Everything

The third part of MonitLabs’ study introduced a critical layer of nuance by breaking the data down by industry — and it revealed that aggregate-level analysis can be misleading.

When analyzed industry-by-industry, correlations between backlinks/authority and visibility strengthened significantly compared to the merged dataset. This is a textbook example of Simpson’s Paradox: when you combine data from different competitive contexts, the true relationships get diluted.

Consider this: a finance site competing for complex medical insurance queries operates in a fundamentally different competitive landscape than a hobby blog covering knitting patterns. Merging their data washes out the competitive dynamics that actually determine who ranks.

For traditional SERPs, the industry-level Spearman correlations for backlinks ranged from roughly 0.24 to 0.32 — notably stronger than the aggregate 0.22. Industries like Beauty & Personal Care, Finance, Health, and Hobbies & Leisure showed particularly robust relationships between backlinks and SERP visibility.

The AI Overview picture was more varied:

For AIO, most industries showed Spearman correlations clustered near zero, with some going slightly positive (Hobbies & Leisure, Retailers & General Merchandise) and others slightly negative (Home & Garden, Beauty & Personal Care). Pearson values were more consistently positive across industries but still relatively weak (0.05–0.28 range).

The key takeaway

if you’re making SEO decisions based on aggregate-level studies alone, you’re likely missing the competitive reality of your specific industry. Always contextualize ranking factor research within your vertical.

What This Means for Your SEO Strategy

MonitLabs’ research paints a nuanced picture that should inform how SEO professionals think about link building, authority metrics, and the emerging AI search landscape. Here are the practical takeaways:

Looking Ahead

MonitLabs has indicated that additional research is forthcoming, including analysis of Google’s AI Mode, multi-LLM comparisons across platforms like ChatGPT and Perplexity, and sentiment analysis integration. These follow-ups will be valuable as the relationship between traditional SEO signals and AI-driven search continues to evolve.

For now, the data is clear on one front: the era of “just build more backlinks” as a catch-all SEO strategy is fading. The search landscape is becoming more nuanced, and the data supports a more balanced approach — one that weighs backlinks alongside content quality, topical depth, search intent alignment, and industry-specific competitive dynamics.

This article is based on the three-part Ranking Factors Study conducted by MonitLabs, led by founder Grzegorz Czapik. Data was collected in November 2025 across 27,204+ domains and 24,000+ keywords. All charts and visualizations in this article are sourced from MonitLabs’ original research. We thank MonitLabs for their rigorous, data-driven contribution to the SEO community.