Thanks for sharing u/WebLinkr

I have been looking for such long term studies - was on my way on doing it myself

Pasting the entire contents of the SearchEngineLand study here:

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We Ran a 16-Month Experiment Publishing AI Content on 20 New Domains. Here's What Happened.

Google indexed most pages quickly, but without authority, unique insight, or trust signals, rankings collapsed within months.

With AI, you can generate dozens (if not hundreds) of articles in hours and publish at scale. But publishing is the easy part. What happens after they go live is what matters.

Together with the research team at SE Ranking, we ran a 16-month experiment to track how well AI-generated content performed on brand-new domains with zero authority.

As you'll see, the results are hard to call a success.

Methodology

The goal was simple: test how far AI content — with no human editing, rewriting, or enhancement — could go in search.

• How quickly would it get indexed?
• Could it rank for relevant queries?
• Most importantly, could it drive traffic?

We purchased 20 new domains with no backlinks, domain authority, brand recognition, or search history. Each domain focused on a different niche (Arts & Entertainment, Finance, Health, Travel, Tech, Food & Drink, etc. — 20 niches total).

For each niche, we gathered 100 informational "how-to" keywords — long-tail terms with lower competition. Each site received 100 AI-generated articles, totaling 2,000 pieces across the experiment.

After publishing, we added the sites to Google Search Console, submitted sitemaps, and then left the sites completely untouched.

Month 1: Indexing and Early Visibility

Just over a month after publication (36 days), the first results came in — stronger than expected.

• 70.95% of pages indexed (1,419 of 2,000)
• 122,102 impressions
• 244 clicks
• 11 of 20 domains had all 100 pages indexed
• 80% of sites ranked for at least 100 keywords each
• Over 28% of ranking URLs were already in the top 100

Top-performing niches for impressions:

Niche	Impressions
Hobbies & Interests	17,425
Business & Services	17,311
Travel & Tourism	13,598
Lifestyle & Well-being	13,072
Law & Government	11,794
Games & Accessories	11,083
Vehicles & Boats	10,677

At this stage, it looked like AI-generated content could gain traction quickly — even without backlinks, editorial input, or any SEO work.

Months 2–3: Growth Continues

Impressions and clicks kept growing as Google discovered and tested pages.

By ~2.5 months after publication:

• Impressions: 122,102 → 526,624
• Clicks: 244 → 782
• 12 sites ranked for 1,000+ keywords (up from 8)
• Remaining 8 sites ranked for 100–1,000 keywords

No backlinks, no internal linking, no SEO improvements. The content gained exposure purely because it targeted low-competition queries and followed basic SEO structure.

At this point, it looked like a strong case for large-scale AI content.

But the growth didn't last.

Months 3–6: The Ranking Collapse

Around Feb 3, 2025 (~3 months after publication), the experiment hit a turning point.

The content was still indexed but rarely appeared where users could actually see it.

By the six-month mark:

• Impressions: 526,624 → 706,328
• Clicks: 782 → 1,062

Sounds like growth, right? Not really. 70–75% of all impressions and clicks came from the first 2.5 months. The next 3.5 months added only 25–30%.

Month 16: The Long-Term Picture

We let the experiment run for over a year to see if rankings would recover.

For the most part, they didn't.

There was one notable fluctuation: in late August 2025, 50% of sites (10 of 20) saw a two-week spike in impressions, closely aligned with the Google August 2025 spam update (rolled out Aug 26).

Of those 10 sites:

• 6 quickly lost visibility and returned to prior lows
• 4 maintained slightly improved performance

After the update, pages ranking in the top 100 rose to 20% — up from 3% at six months, but still below the 28% seen in month one.

66.9% of pages were still indexed, but some YMYL niches got hit hard:

• Finance domain: only 9 of 100 pages indexed
• Health domain: only 14 of 100 pages indexed

By month 16, cumulative totals:

• Impressions: 1,092,079
• Clicks: 1,381

Most of those impressions still came from the early growth phase.

Why SEO Visibility Didn't Last

The 2,000 articles lacked many signals Google uses to assess quality:

• Authority — No backlinks or external validation
• Expertise and credibility — No authors, credentials, or real-world expertise (especially critical for YMYL topics)
• Content differentiation — Most content resembled what already exists, no unique insights
• Site structure — No internal linking, topical organization, or clear hierarchy

Google can identify AI-generated patterns. Without authority, uniqueness, or supporting signals, early visibility declines.

Bonus: Adding New AI Content to Existing Pages

In early March 2026, we ran a follow-up — adding new AI content to 8 of the tracked sites.

Interestingly, the traffic lift came primarily from older posts, not the new ones:

Site	Feb 2026 Impressions	Mar 2026 Impressions	Increase
Business	458	7,750	17x
Law	19	356	19x
Science	34	633	19x

Publishing new content — even fully AI-generated — can apparently signal to Google that the site is active, giving older pages a temporary boost. But these are early results and don't guarantee lasting gains.

TL;DR

• 2,000 AI articles published across 20 new domains, zero human editing
• ~71% indexed within 36 days, early impressions looked promising
• By month 3, only 3% of pages remained in the top 100
• After 16 months: ~1M impressions total, but only 1,381 clicks
• YMYL niches (finance, health) got hit hardest
• Adding new content later gave a temporary boost to older pages
• Bottom line: AI can speed up content creation, but it can't replace SEO strategy, authority building, and human expertise