Semrush underestimates your real traffic: the impact of AI Overviews on forecasts

A client calls me, Tuesday morning. He invested $8,000 in an SEO campaign based on Semrush.

He is proud. His Semrush forecasts show +220% potential traffic on his key pages. He budgeted $8,000 for content, links, time. The contract is signed.

Four months later, real traffic has only grown 12%. Not 220%. 12%. The gap? 200% frustration.

I dig deeper. His pages rank well. Several are in position 1 or 2. Yet clicks don’t follow. Why?

The answer is in the SERP. On his main keyword, an AI Overview occupies the first 200 pixels. The source link is cited but lost in the summary. The real click-through rate on his page is 4%. Semrush had promised 30%.

This isn’t an isolated case. I review 15 sites per week. All show the same gap.

Why Semrush overstates your traffic (and why it makes sense)

Semrush uses a historical CTR formula inherited from studies conducted 15–20 years ago. The rule: position 1 = 30% of search volume, position 2 = 15%, position 3 = 10%, and so on. This rule was already rough-and-ready back then. In 2026, with the arrival of AI Overviews, featured snippets, videos, and carousels, it has become purely theoretical.

A recent post on r/SEO describes the problem perfectly: « Nobody clicks your source link in an AI Overview the way they would if you were number 1 in 2005. » One contributor reports that his client, despite ranking first on a high-volume keyword, receives only 50 clicks per day, where Semrush had predicted over 500.

Here’s what’s actually happening:

• AI Overview: the snippet integrates the answer. The user doesn’t need to click. Even if your link is cited, CTR drops to 2–5%.
• Featured Snippet: content displays directly. CTR can fall to 5–8% for the source page.
• Google Shopping ads: push organic results lower, further reducing visibility.

Semrush doesn’t account for these elements in its traffic estimate calculation. It treats each position as if the SERP were still a list of ten blue links.

Result: your dashboards give you an illusion of growth. You invest where reality is far more modest.

What I observe with my clients: the average gap is 40–60%

For the past six months, I’ve systematically compared Semrush estimates against real Google Search Console data for my e-commerce clients. Sample size: about twenty sites, ranging from 500 to 50,000 pages.

Here are a few numbers:

• Client A (800-item catalog): Semrush estimated 4,500 sessions/month for his main keyword. Real: 1,200. Gap: 73%.
• Client B (cosmetics brand): Semrush predicted 2,800 sessions. Real: 900. Gap: 68%.
• Client C (B2B site): 1,500 estimated, 700 real. Gap: 53%.

The average gap across the sample is 47%. And it grows as AI Overviews roll out across more queries.

A Search Engine Journal article from March 2025 confirmed this trend: for queries with AI Overview, the CTR of the first organic result falls on average 40–60% compared to a SERP without an overview.

If you pilot your SEO budget purely on Semrush estimates, you risk under-investing or setting unrealistic targets. You spend for traffic that doesn’t exist.

The counterintuitive part: Semrush is still a fantastic tool — but you need to recalibrate

I don’t discard Semrush. I use it every day. For keyword research, competitive analysis, rank tracking — it’s excellent.

But estimated traffic must be manually revised. It’s like a car whose speedometer reads 140 km/h when you’re actually driving 90. You don’t throw away the car. You recalibrate the gauge.

The problem isn’t Semrush. It’s the failure to update their CTR model against new SERP realities. That’s understandable: modeling the impact of each feature would be complex. But in the meantime, you have to do the filtering.

The good news: you can correct estimates easily. Here’s how.

Recalibrate your Semrush estimates in 3 steps

Step 1: Download your GSC data over 3 months. Extract clicks, impressions, and positions for your main pages. Compare against Semrush estimates for the same keywords.

Step 2: Calculate your own average CTR by position. For example, for position 1 where an AI Overview is present, your real CTR might be 8%. Apply this ratio to future estimates.

Step 3: Use a correction factor. If you find a 50% gap for high-stakes queries, divide Semrush estimates by two. For queries without AI Overview, the gap is smaller (20%).

With my clients, I integrate this into the DOSE framework (Diagnosis, Optimization, Tracking, Expansion) that I learned from Guillaume Attias at BMO Academy. This lets us set realistic targets and allocate budgets where returns are real.

Concrete example: with one client, we lowered Semrush forecasts by 40%. Result: his traffic target dropped from 10,000 to 6,000 sessions. Over six months, he hit 6,200. No surprises. No disappointment.

And when AI completely cannibalizes your clicks?

Sometimes, even after recalibration, traffic stays low. The AI Overview answers the question fully. Users don’t click at all.

In that case, the solution isn’t to chase position 1. It’s to become the cited source in the AI Overview, sure. But more importantly, to target transactional keywords where AI can’t fully satisfy the user.

Example: for a photography equipment e-commerce store, « best camera for beginners » is cannibalized by an AI Overview. But « buy Canon EOS R10 cheap » remains highly clickable. The CTR estimated by Semrush for that query is 25%. Real: 18%. Still acceptable.

SEO in 2026 isn’t won on informational queries. It’s won on transactional and commercial keywords. Those where the user needs to compare, see price, add to cart. AI doesn’t replace the purchase act yet.

If Semrush shows you high search volume on an informational keyword, be cautious. Real traffic will be much lower. Conversely, a low-volume but highly transactional keyword can deliver more sales.

How this changes your SEO strategy (and your budget)

First, don’t take Semrush traffic estimates as gospel. Use them as a relative order of magnitude, not absolute.

Second, invest in first-party data. Google Search Console is your best ally. Set it up correctly, track trends over 12 months, not 7 days.

Third, adjust your targets. If you aim for 30% growth based on Semrush estimates, you risk disappointment. Base yourself on your real numbers plus a correction factor.

Finally, think about traffic quality. A visitor arriving via an AI Overview is often less engaged. Bounce rate is higher, time spent is lower. Better fewer visitors, but more qualified ones.

I see it every day: e-commerce teams that recalibrate expectations and focus on transactional traffic achieve far better ROI. Those who persist in chasing estimated volumes waste their budget.

Stéphane Jambu

SEO & AI Engineer

I build growth systems / AI / Neuroscience | 650+ clients · 80 LinkedIn testimonials · 30 years of expertise · 15 years of systems running without me.

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