The 400-slide strategy has had its day: why strategy work is moving back in-house

Summary: Companies are bringing more and more marketing work in-house. According to the GWA AI Whitepaper 2026, 80 percent of the marketing decision-makers surveyed want to do more in-house in the future. Classic strategy work is the next logical step. The common agency model delivers strategy as a presentation: elaborately developed, quickly outdated and hard to adapt. Delays build up between strategy and execution, every adjustment becomes a project, and when the market shifts, the strategy stays stuck in the deck. Agencies remain valuable for creative and operational execution, for example in campaigns, branding or ad assets. Ongoing strategy work belongs where execution happens. This article explains why and what teams need to lead strategy themselves.

The division of labor between companies and agencies is being reorganized.

For the GWA AI Whitepaper 2026, the German Association of Communication Agencies (GWA) and the Handelsblatt Research Institute surveyed 170 CEOs and CMOs. The result is clear: 80 percent of marketing decision-makers want to do more in-house in the future. This most often concerns research and market research (52 percent), followed by creative work (50 percent) and the production of ad assets (44 percent). Companies see the biggest lever of AI in efficiency gains (61 percent), greater effectiveness (54 percent) and cost reduction (49 percent).

Agencies are moving too. According to the study, 76 percent have already introduced AI-based products or services. The industry is working on new value creation models.

Strategy work does not appear explicitly in the study's list. A recent study from the US, however, shows where things are heading: in the 2026 State of In-Housing Report by the Association of National Advertisers (ANA), just over half of respondents (53 percent) see the most important role of internal marketing teams as acting as a strategic partner in upstream strategy. Only 9 percent still view in-housing primarily as a cost-saving measure. A few years earlier, cost savings were still the main motive.

As companies increasingly take on research, analysis and creative work themselves, the strategy built on these foundations becomes an in-house topic as well. And that is exactly where the weaknesses of the classic model are greatest.

How classic strategy work with agencies works

The process is similar in many companies:

1. Briefing: The company describes its starting point and goals.
2. Analysis: The agency conducts interviews, evaluates market and competitor data and facilitates workshops.
3. Development: Over weeks or months, positioning, target groups, messages and activities take shape.
4. Handover: The end result is a presentation. Often with several hundred slides.
5. Execution: The company executes the strategy, usually in its own tools and with its own teams.

This model worked for a long time. In markets that change slowly, a strategy that is developed carefully once and then executed over years is enough.

Today, it creates four structural problems.

Four problems of the classic agency model

1. The strategy ends up as a presentation

The result of classic strategy work is a document. It can be excellently thought through, with market analyses, persona profiles, positioning models and action plans.

In day-to-day work, however, hardly anyone works with this document. 400 slides can be presented, but they can't be used to steer. The connections between goals, target groups and activities are spread across different slides and can't be tracked. And the knowledge of why a decision was made often stays with the people who built the presentation.

→ Why strategy work fails today – and how growth teams can move faster

2. Delays build up between strategy and execution

From analysis to the finished presentation, weeks or months often pass. By the time of handover, the data the strategy is based on is already somewhat dated.

Then the translation into execution begins. Slides have to become campaigns, budgets, tasks and KPIs. This translation happens in other systems, often by other people. Context gets lost along the way, and the link between strategic intent and daily work grows thinner every week.

3. Adjusting course becomes a project

Strategy needs adjustment. A target group responds differently than expected, a channel delivers less than planned, an assumption turns out to be wrong.

In the agency model, every major adjustment means a new briefing, alignment, a proposal and scheduling. Each of these loops costs time and budget. That is why adjustments are often postponed, bundled or skipped entirely. A company's response time then depends on the rhythm of the collaboration rather than on how fast the market moves.

→ What alignment really costs

4. When the market shifts, the strategy stays behind

Markets are changing constantly today. New competitors, changing customer needs, new channels, new technologies.

The presentation doesn't change with them. It stays at the state of its handover. Teams start to improvise, adjust activities on a small scale and drift step by step away from the official strategy. At some point there are two strategies: the one in the deck and the one people actually work by.

By then at the latest, the strategy has died in the presentation.

What agencies are still needed for

This doesn't make agencies obsolete. Going forward, their strength lies above all in operational execution: where creative excellence is required or internal capacity isn't enough.

• Creative campaign execution: A planned initiative becomes a campaign idea that stands out. Concept development, storytelling and ideation are classic agency strengths.
• Branding and brand development: Anyone building a new brand or planning a rebrand benefits from specialized design expertise.
• Designing ad assets: Ads, videos, landing pages and sales material in high quality and volume.
• Expertise in individual disciplines: for example performance marketing, SEO, PR or social media, when specialist knowledge is missing internally.
• Additional capacity: for launches, campaign peaks or phases when your own team is at full capacity.

This makes the division of labor clearer. Strategy, steering and adjustment sit within the company. Agencies come in specifically where creative and operational excellence is needed. They receive a clear briefing derived from the strategy: goal, target group, expected impact and the KPI the activity will be measured against.

Voices from the agency world itself now recommend this division of labor. In an article for the German tech publication t3n, Simon Mader, co-founder of the social performance agency Adbaker, advises companies to develop strategy and corporate identity in-house and to hand operational tasks to service providers.

The GWA Whitepaper describes this shift from the agencies' perspective: the value of agency services is changing, and with it the way companies and agencies work together.

Why strategy work belongs in-house

Four developments make it both possible and sensible to lead strategy work yourself today.

Strategy work follows repeatable patterns. The questions strategy work starts with are similar from company to company: What do we stand for? Who do we want to reach? Which initiatives will get us to our goal? The frameworks for answering them are proven too. What is unique is the context: your business, your market, your data. When the methodology lives in a system, a team can apply it themselves, and the context stays where it emerges.

Strategy is an ongoing process. When markets change constantly, strategy has to adapt constantly too. That only works where people deal with data, customers and results every day.

The people who execute need the strategy in their daily work. Anyone steering campaigns, allocating budgets and setting priorities needs to know why a decision was made and what it contributes to. This knowledge has to live within the company.

AI lowers the barrier. Analyses that used to take weeks of external work can now be done in hours. That is exactly why 61 percent of the companies surveyed in the GWA Whitepaper see the biggest lever of AI in efficiency gains. The prerequisite, however, is that AI knows the full strategic context.

→ Why ChatGPT and other AI tools don't understand your strategy

What teams need to lead strategy themselves

Bringing strategy work in-house takes more than an internal copy of the agency presentation. Four things are essential:

1. A shared model: Positioning, target groups, goals, initiatives and KPIs live in one place and are connected.
2. A link to execution: Strategy and execution work with the same model. This keeps it visible whether initiatives are contributing to their goals.
3. Ongoing insights: Problems and potential become visible as soon as they emerge, without anyone having to look for them specifically.
4. Fast adjustment: Changes to the strategy happen directly in the system, without a briefing and without a project loop.

How cosmos™ makes in-house strategy work possible

cosmos™ is an AI-powered growth strategy platform for growth teams and decision-makers. cosmos™ is built on twelve years of brand and growth strategy work. Methods and frameworks from that time have gone into the platform. That is why we know the agency model described in this article from our own experience, including the presentations that hardly anyone opens after handover. The platform turns the strategic work that traditionally ends up in an agency presentation into a living model within the company: from the strategic foundation to execution.

Building the strategic foundation in your own system: Positioning and personas are created directly in cosmos™. The strategic foundation that is traditionally developed in an agency's analysis phase sits inside the company from day one and can be adjusted at any time.

Strategy in one place: Positioning, target groups, goals, initiatives and KPIs are connected in cosmos™. The connections that are spread across hundreds of slides in a deck stay visible at all times.

Planning with scenarios: New initiatives are planned directly within the strategic big picture. Scenarios can be played through in advance: What happens if we invest more here? Which dependencies arise? On request, the AI suggests how an initiative could be set up based on proven practices.

Execution in the same model: Execution runs against the same model it was planned in. The data comes from the systems the company already uses. This makes it continuously visible what is working and where deviations occur.

Spotting problems and potential early: The AI in cosmos™ continuously analyzes the full context and makes visible where action is needed, for example when an initiative has been falling short of its expected impact for weeks.

Adjusting without a project loop: When the market shifts, the team adjusts the strategy directly in the system. The change is immediately visible to everyone who works with it.

When agencies execute individual activities, their impact can be measured in the same model. This keeps it visible how creative work contributes to the goals.

Agency model vs. strategy in your own system

	Classic agency model	Strategy in your own system
Strategic foundation (positioning, personas)	Developed by the agency, documented in the deck	Developed in your own system and continuously adaptable
Output	Presentation	Living model
Timeliness	As of handover	Continuously updated
Link to execution	Manual translation into other tools	Execution in the same model
Adjustment	New briefing, new alignment loop	Directly in the system
Knowledge about decisions	Often with the agency	Within the company
Response to market changes	At the pace of the collaboration	As soon as they become visible

Self-check: is your strategy stuck in a presentation?

1. When did someone on your team last open the strategy presentation? If the answer is "at the last review," it barely steers day-to-day work.
2. How long does it take to adapt the strategy to a market change? If it requires a briefing, the response time is too long.
3. Can your team say which goal an ongoing initiative contributes to? If not, the link between strategy and execution has been lost.
4. Does actual practice differ from the official strategy? Then there are already two strategies.
5. Does the knowledge about your strategic decisions live within the company? Or would you have to ask the agency why something was decided the way it was?

Conclusion: strategy belongs where execution happens

Companies are increasingly bringing marketing work in-house. Classic strategy work is following this trend because its traditional format is reaching its limits. A strategy handed over as a presentation becomes outdated as soon as the market moves.

Agencies keep their value in creative and operational execution. Ongoing strategy, however, has to live where decisions are made and executed every day: within the company, in a system that changes with the market.

A company's strategic core is too important to rent. It should belong to the company and work in everyday practice, on every Monday morning just as much as at the offsite.

The key question is therefore: Where does your strategy live today, in the deck or in your team's daily work?

Sources:

• GWA & Handelsblatt Research Institute: GWA KI Whitepaper 2026 (survey of 170 CEOs and CMOs, in German)
• Association of National Advertisers (ANA): The Resilient Rise of the In-House Agency – 2026 State of In-Housing Report
• Simon Mader (Adbaker): "Marketing ohne Agentur: So baust du effektives Inhousing auf," t3n (in German)