You have a marketing budget. You know GEO will become unavoidable. The question: external agency or internal capability?
Short answer: it depends on who can own the topic internally. Not budget. Not urgency. The availability of someone who can carry the topic week after week.
The GEO agency: fast start, prolonged dependency
When it fits. Three cases where an agency is the right choice:
- You don't have an SEO or content team in-house. Nobody has the bandwidth to absorb a new scope.
- You want to start in under 6 weeks with a methodology already tested on other brands.
- Your niche is highly competitive and requires fan-out analysis depth beyond what one person can deliver.
What you pay. $1,800 to $8,500 per month depending on scope. The low end covers 20-30 prompts on 3 LLMs, no content execution. The high end covers 80-200 prompts on 7 LLMs with production of 2-4 articles per month.
What you gain. Proven methodology, access to competitive benchmarks (the agency sees what works for its other clients), operational reactivity.
The hidden cost. Dependency. After 12 months, you know what to do but you haven't internalized the capability. If the agency changes its team or you change agencies, you start over on program knowledge.
In-housing: ramp-up, full control
When it fits. You already have a mature SEO or content team, and at least one person willing to add GEO to their scope.
The right profile. Three types of people can own GEO in-house:
- A senior SEO adding GEO to their scope. Fast learning curve because fundamentals overlap.
- A content manager with strong data sense. Ideal for execution but needs technical support on the tracking stack.
- A multi-channel growth marketer integrating GEO into their acquisition stack.
Juniors or 100% writer profiles don't fit. GEO requires analytical rigor: reading dashboards, cross-referencing signals, prioritizing actions.
What you pay. Tooling: $85 to $325 per month for a tracking platform like Mentionable. Internal time: 4 to 8 hours per week from the person who owns it.
The real math. For an in-house SEO paid $75,000 annually, 4-8 weekly hours represent $750 to $1,500 per month in analytical cost. Total: $800 to $1,800 per month.
Comparison: a comparable agency costs $3,500 to $5,800 per month. In-housing divides the cost by 3-5x.
The hidden cost. Time. Plan for 3 to 6 months before a senior SEO becomes autonomous on GEO workflows (tracking, fan-out, content optimization). First 30 days for tools. Next 60-90 days to build operational pipelines. From month 4, the internal team becomes more effective than an external agency because it knows the business context better.
The hybrid path: 90 days of agency, then in-house
This is the path most serious B2B brands take.
Phase 1 (months 1-3): agency. Scoped 90-day engagement with an agency to:
- Initial audit (current state, identification of business-critical prompts)
- Tracking setup (LLM selection, prompt calibration)
- First prioritized action plan
- Internal team training (workflow, tools, methods)
Phase 2 (month 4 and beyond): in-housing. The internal team takes over daily ops: monitoring, fan-out analysis, content execution. The agency stays on backup for strategic topics or peak loads.
What it costs. Phase 1: $7,000 to $18,000 in setup. Phase 2: $800 to $1,800 per month (tooling + internal time). Over 12 months, total cost is 30-50% lower than a pure agency engagement.
Why it works. You pay the agency for what it does best (structuring a program from scratch) and the internal team for what it does best (operating over time with business knowledge).
When to hire a dedicated GEO specialist
Not before the volume justifies it. A brand tracking 30-50 prompts on 3-5 LLMs doesn't need a dedicated GEO specialist. An SEO or content manager can absorb the work.
The dedicated profile becomes relevant from:
- 100-200 tracked prompts
- Multiple brands in portfolio (agency or group)
- International ambition (multi-market, multi-language)
Below this threshold, dedicating an FTE to GEO creates idle time.
The decisive criterion
Not budget. Not urgency. The availability of someone who can own the topic internally, week after week, for at least 6 months.
If that person exists: in-house with a tool and 4-8h per week. If they don't: hire an agency for 90 days, long enough to structure the program and hire or train that person.
Finding an agency to start
If you choose the hybrid path and need an agency for the first 90 days, Mentionable maintains a hand-picked directory of GEO agencies and consultants. Several offer scoped 90-day engagements designed to transition to an in-house team. No commission, no paid placement.
