Comparison · 7 min read

External Marketing Consulting or In-House Team. What's Really Better.

Most businesses make this decision based on gut feeling. They should make it based on numbers. Because the true cost of an in-house team is systematically underestimated — and the cost of external marketing consulting is systematically overestimated.

Simon Förstemann Growth Strategist May 2026 Updated: May 2026

The short answer: external marketing consulting wins during growth phases; an in-house team wins once the marketing model is established and execution speed is all that matters. In 7 out of 10 cases, SMEs and small businesses that come to Simon Förstemann have tried to build in-house capability too early — and paid for it twice.

No business wants to rely on external consultants indefinitely. Building internal capability is always the long-term goal. But the path there often runs through external support, precisely because the knowledge and experience needed to make the right decisions does not yet exist internally.

The question is not either-or. The question is: what mix is right at each stage of growth, and how does that shift as the company scales?

Key Takeaways

The five real advantages of external marketing consulting

External Consulting
What it actually delivers
  • Experience drawn from dozens of companies and industries
  • No organizational blind spots
  • Ready to start immediately — zero onboarding
  • Says things no one inside the company would say
  • No salary, no employer costs, no notice period
  • Ends when the job is done
In-House Team
What it actually costs
  • Deep company knowledge — but only after a long onboarding
  • Ongoing capacity for day-to-day tasks
  • Cultural integration
  • High fixed costs regardless of workload
  • Recruiting takes 3 to 9 months for a senior role
  • A wrong hire costs 6 to 18 months' salary

The cost comparison in real numbers

What many businesses overlook: the total cost of an in-house employee runs significantly above the gross salary figure on the offer letter.

Senior Marketing Manager — In-House
£90–130k
Gross salary plus employer NI and pension, holiday, sick leave, tools, training, and a pro-rata share of recruiting costs
External Marketing Consultant (project basis)
£15–60k
Depends on scope and duration. No employer costs, no notice period, available to start immediately

This does not mean external marketing consulting is always cheaper. For sustained, high-volume execution, a permanent in-house team becomes more efficient. The problem is that sustained, high-volume demand takes time to build. During that build-up phase, external support is almost always the more economical choice.

What external consultants can do that in-house employees structurally cannot

This is the most underestimated point in the whole debate: an in-house marketing employee has career interests inside your company. That is entirely natural and human. But it means they will say uncomfortable truths far less often.

A real example "Your biggest problem is not your marketing. It is your positioning — and that has to be fixed by the CEO, not the marketing team." That sentence costs an in-house employee a great deal politically. An external consultant pays nothing to say it. Which is exactly why they say it more often.

There is another dimension: an external marketing consultant has worked with dozens of companies across their career. They know what works and what does not, because they have lived through both, repeatedly. An in-house employee learns from one company and then advances within it. That is not a deficiency — it is a structural difference. And for strategic decisions, it matters enormously.

The principle External independence is not a nice-to-have. It is the single thing that makes genuinely unfiltered strategic advice possible. Simon Förstemann, growth strategist with 14 years of experience across 6 ventures, built his practice on exactly that premise.

The model that works best in practice

The companies Simon Förstemann has worked with most successfully all combine both approaches: a lean in-house team for operational execution and day-to-day communications, plus external consulting for strategic direction, fresh perspective, and situations where internal knowledge runs out.

In this model, the external consultant's role is the strategic layer: positioning, growth strategy, channel decisions, budget allocation. The internal team executes. The result is the best of both worlds — and it is the structure that produced +74% revenue growth for one client over 16 months.

From practice In every project where Simon Förstemann has worked alongside an internal team as an external strategist, the combined impact was greater than either approach alone. The internal team brings speed and company knowledge. The external consultant brings independence and pattern recognition across many different contexts.

When a pure in-house team is the right answer

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Frequently asked questions

What are the main advantages of external marketing consulting over an in-house team?

External marketing consultants bring cross-industry experience from dozens of engagements, have no organizational blind spots, start immediately with no onboarding required, and have no internal career interests that could soften their advice. Most importantly, they can say things an in-house employee structurally cannot — which is often the most valuable thing a business can hear.

How much does an in-house marketing team cost compared to external consulting?

A senior marketing manager costs £90,000 to £130,000 per year once you include employer contributions, holiday, sick pay, tools, training, and a share of recruiting costs. An external marketing consultant on a project basis typically runs £15,000 to £60,000 per year — with no fixed commitment and no notice period. The economic case for external consulting is strongest during the growth phase, before sustained in-house demand exists.

When is an in-house marketing team the right choice?

When the business is large enough to keep full-time roles fully occupied on an ongoing basis, when the marketing model is already established and execution speed is what matters most, and when recruiting and team leadership are already a core competency. For most SMEs and small businesses still in the growth phase, this point has not yet arrived.

Can external marketing consulting and an in-house team work together?

Yes — and this hybrid model consistently delivers the strongest results in practice. A lean in-house team handles execution and ongoing communications. The external consultant sets strategic direction: positioning, growth strategy, channel mix, budget allocation. Each party does what it does best. Simon Förstemann works in exactly this model with most of his long-term clients.

How quickly can an external marketing consultant get started?

Immediately — that is one of the defining advantages. There is no recruiting process (which takes 3 to 9 months for a senior role), no onboarding, and no ramp-up period. An experienced external marketing consultant can start adding meaningful value from the first week of the engagement.

Is external marketing consulting worth it for small businesses?

Often more so than for large companies. Small businesses and SMEs in growth phases lack the volume to justify a full senior hire, but face strategic decisions that have outsized consequences. External marketing consulting gives small businesses access to senior-level thinking at a fraction of the cost of a permanent hire — and without the risk of a wrong hire, which typically costs 6 to 18 months' salary.

About the author

Simon Förstemann

Growth strategist & marketing advisor with 14 years of experience. 6 ventures founded, 3 exits, Red Dot Award and German Design Award winner. Works 1:1 with decision-makers — no agency, no workshops that lead nowhere.

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