Research
What correlates with AI brand mentions? Ahrefs' 75,000-brand study
Ahrefs correlated 12 metrics with brand mentions in ChatGPT, AI Mode and AI Overviews: web mentions beat backlinks, and it warns of no causation.
Original research
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Method-first investigations with a stated hypothesis, sample and published limitations.
Research
How accurate are sitemap lastmod values? Bing's study
Bing's own study of sitemaps found 18% of lastmod values set incorrectly, usually to the generation date, and Google says it only trusts accurate ones.
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Do AI assistants cite fresher content than Google? Ahrefs data
Ahrefs compared the age of 16.975 million URLs cited by AI assistants against organic Google results. Here is the method, the numbers and the limits.
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Reddit's top-3 share after the May 2026 core update
SE Ranking tracked 100,000 keywords in 20 niches and measured Reddit's share of Google's top three results. This piece reviews its method and limits.
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Sistrix CTR study: how SERP layout changes position-1 clicks
Sistrix analyzed 80 million keywords and found position 1 averages 28.5% CTR, ranging from 13.7% to 46.9% depending on the SERP layout.
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A randomized field experiment on AI Overviews and organic clicks
A randomized Chrome-extension experiment hid AI Overviews for 1,065 searchers. This piece analyzes Agarwal and Sen's SSRN study of the CTR impact.
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What happened when someone actually A/B tested author bylines
SearchPilot ran a real controlled SEO split test on author bylines and bios. Result: no detectable ranking gain, and possibly a small loss.
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SearchPilot test: canonical alone matched a redirect for duplicates
A SearchPilot split test added 301 redirects atop an existing canonical tag for trailing-slash duplicates. The result stayed inconclusive.
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What a 10M-page site shows about links and crawl budget
Botify's case study of a US auto marketplace ties internal-link depth to crawl activity: a 19x increase in crawling once linking was fixed.
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Why title rewrite rate studies disagree: 33% vs 61% vs 76%
Ahrefs found a 33.4% title rewrite rate, far below Zyppy's 61.6% and Search Engine Land's 76%. The gap traces to how each study defines a match.
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Who blocks AI crawlers: 60 robots.txt files, read in full
We read the robots.txt of 60 publishers and SEO vendors. News sites block AI crawlers almost universally. The SEO industry does not.
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Do internal links still track with Google Search traffic in 2026?
Zyppy's 23-million-link study and Google's own crawling documentation show why pages with few internal links struggle to get discovered and clicked.
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Review and AggregateRating schema: Google's real required fields
Google's own review-snippet documentation names exact required properties and exact abuse rules. Most markup fails one of those, not from being absent.
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Pagination and infinite scroll: what Google actually indexes in 2026
rel=next/prev has been dead as an indexing signal since 2019, per Google's own words. Infinite scroll without real URLs is the same mistake in new clothes.
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Do backlinks still correlate with rankings in 2026?
Backlinko's 11.8M-result study and Ahrefs' 1M-keyword study both find a positive link between referring domains and rank, but the coefficient is weak.
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Hreflang error rates: what's actually sourced, and what isn't
Two widely repeated hreflang error statistics do not trace to any real source. Here is what could be verified instead, from Google's own documentation.
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AI citation hallucination rates: what three real studies found
GPTZero, the Tow Center and a Cureus study each measured AI citation hallucination differently, and none of their numbers agree with each other.
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What academic research actually says about AI citation factors
Four 2026 papers measured what predicts citation by AI search engines. Position and relevance win; most citations skip brand domains entirely.
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Noindex does not save crawl budget, per Google's own documentation
A common crawl-budget fix is backwards. Google's own documentation says noindex still costs a full request before the page gets dropped from the index.
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Site reputation abuse: what the evidence actually shows
Google's manual actions against parasite SEO are 18 months old. Here is what is documented versus what is anecdotal case tracking.
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NavBoost: what the DOJ trial and the API leak actually confirmed
Court testimony and a leaked Google document, read together, describe a click-based re-ranking system Google spent years declining to confirm in public.
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VideoObject schema: the required properties Google actually documents
Google documents three required VideoObject properties, not the four often claimed, plus exact date and duration formats and a rich-result caveat.
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Core Web Vitals and rankings: what the correlation shows
CrUX data and a 20,000-URL ranking study both show a link between Core Web Vitals and rank, but Google's own docs put content relevance first.
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Googlebot's two-wave rendering: how long JS content actually waits
A 2024 Vercel and MERJ study measured the real gap between crawl and render at scale. The median was seconds; the tail stretched to a full day.
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E-E-A-T and author schema: what is actually verifiable
SEO content repeats precise E-E-A-T ranking-weight percentages. We checked the two most-cited figures against their sources and Google's own documentation.
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Does content length correlate with rankings and AI citations?
Ahrefs' December 2025 study puts the word count to AI Overview citation correlation at 0.04. Backlinko's 11.8M-result study finds no ranking edge either.
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What Google actually names in its own ranking systems guide
Google publishes a real, maintained list of the named systems behind Search ranking. Read directly, not summarized secondhand.
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Local ranking factor percentages: what's real, what's not
A specific local ranking percentage breakdown circulates widely. It doesn't match Whitespark's real 2026 chart, and Google names no percentages at all.
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x-default's real history: what Google has actually said, on record
x-default has been explained by Google at least three times since 2013. Here is the real, dated wording each time, and what current documentation says.
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HTTPS as a Google ranking signal in 2026
Google called HTTPS a very lightweight ranking signal in 2014 and has never revised that number. Adoption data now shows why it barely needs to.
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Featured snippet stats: which numbers are real, and which aren't
Featured snippet prevalence and CTR figures vary by nearly 2x across sources. Here is which trace to a real, dated study, and which don't trace anywhere.
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Article schema has no required properties, only recommended ones
Google's own Article structured data documentation names zero required properties, only recommended ones, which changes how schema work gets prioritized.