You're looking at the service pages of five agencies. All show "SEO + GEO". All promise to make you visible on ChatGPT. None deliver the same thing.
The market is young. Many SEO agencies have added a "GEO" line to their landing without changing their method. Others have actually built a new capability. Here's how to tell them apart.
What an SEO agency actually does
An SEO agency optimizes your brand for Google SERPs. Three main levers: authority (backlinks), content (indexable pages targeting keywords), technical (speed, schema, crawl). KPIs measured: Google rankings, organic traffic, conversions from SEO.
Typical stack: Ahrefs or Semrush for keyword research, Screaming Frog for technical audits, Search Console for monitoring, a CMS for content production. Main deliverable: organic traffic growing quarter after quarter.
What a GEO agency actually does
A GEO agency optimizes your brand for citations in LLM answers. Not for Google. For ChatGPT, Perplexity, Claude, Gemini, Grok, Copilot, Google AI Mode and Google AI Overview.
Three main levers: (1) continuous tracking of your citation share per LLM and per business-critical prompt, (2) fan-out query analysis — the queries LLMs run internally to build their answers, (3) optimization of sources LLMs cite in your niche (Reddit, third-party articles, curated lists).
KPIs measured: citation share per LLM, appearance frequency per prompt, mention sentiment, sources cited alongside your brand. Typical stack: Mentionable, Profound or Otterly for tracking, fan-out query analysis tools, source trackers.
The 40% that overlaps
GEO and SEO share fundamentals: domain authority, structured content, trusted sources, speed, schema markup. If your site is invisible to Google, it's invisible to LLMs (they use Google or Bing crawl underneath). A GEO agency that ignores SEO produces content nobody finds.
That's why a good GEO agency almost always has a solid SEO foundation. The reverse isn't true: a good SEO agency can completely ignore GEO and keep delivering excellent SEO work.
The 60% that changes everything
Where GEO and SEO diverge: measurement and optimization.
Measurement. A Google ranking is precisely measurable. An LLM citation is non-deterministic (ChatGPT may cite your brand on the same prompt 60% of the time, then 40% a week later). A GEO agency measures in rolling 30-day averages, not snapshots. An SEO agency that hasn't internalized this difference delivers reports that mean nothing.
Optimization. An SEO article targets a keyword. A GEO article targets fan-out queries — the questions the LLM asks itself internally to answer a user prompt. The format changes: short self-contained paragraphs, numbered citations, explicitly named sources. An excellent SEO article can be a poor GEO article if its chunking doesn't allow extraction by an LLM.
The 3-question test
To find out if your agency really does GEO:
- Which LLMs do you track daily and with what tool?
- What's my current citation share on Perplexity on my 10 most important prompts?
- What are the 5 latest fan-out queries ChatGPT ran internally to answer my business prompts?
A GEO agency answers with recent numbers. An SEO agency that just rebranded "GEO" answers vaguely.
How much it costs
A mature B2B SEO engagement: €1,000 to €5,000 per month depending on scope. A mature GEO engagement: €1,500 to €8,000 per month.
The premium comes from the number of LLMs to track, the volume of fan-out queries to analyze, and the still-scarce expertise. As the market matures, the gap will narrow.
One agency or two?
One, if it truly masters both. GEO work directly benefits from SEO work. Working with two separate agencies creates duplication and coordination cost. The right profile: an agency that has run SEO for 5+ years and added a real GEO capability recently, not the other way around.
Finding a vetted GEO agency
If you want to skip the filtering work, Mentionable maintains a hand-picked directory of GEO agencies and consultants. Every agency has been met by our team and vetted on their tracking stack, methodology and real client results. No commission, no paid placement.
