The Agentic Stack: A UK Founder's Map of the £100bn Opportunity

Let’s be honest. Most of the marketing ‘AI’ you’ve been sold is a lie. It’s a glut of thin-wrapper B2B SaaS products that slap a slick UI on an OpenAI API key and call it revolutionary. It’s prompt-jockeys calling themselves ‘AI experts’ for coaxing a passable email subject line out of ChatGPT. It’s junk.

I say this as someone building AI-native products and running an AI-first marketing agency. The VAST majority of what passes for innovation is derivative, defensive, and doomed to irrelevance. Why? Because these tools are just that: tools. They are passive. They require a human to operate them, to feed them instructions, to check their work. They are hammers waiting for a carpenter.

Agentic AI is the carpenter. It’s not a tool; it’s a worker. An agent is an autonomous system. You give it a high-level goal, access to resources, and the authority to execute. You don’t tell it how to do the job. It figures that out. This is not some far-off sci-fi concept. The foundational pieces are here, right now. And the opportunity to build the definitive marketing agent stack is a £100bn prize that will leave a trail of dead agencies and obsolete SaaS unicorns in its wake.

For the past two years, my team at Creative Marketing Group has been obsessed with this transition. We've moved beyond simple tool-use and into building genuine autonomous systems for marketing execution. The work is gruelling. It forces you to rethink everything from data architecture to client relationships. Along the way, we’ve mapped the new landscape. It's not a single technology but a stack of four distinct layers. Understanding this stack is the first step to seeing where the real value lies.

This is the layer everyone knows. The Large Language Models (LLMs) from OpenAI, Google (Gemini), Anthropic, and a host of open-source alternatives. This is the raw intelligence, the engine. It’s a commodity. Let me repeat that: the core intelligence is rapidly becoming a low-margin utility. If your business model is based on having slightly better access to GPT-4, you are building on sand. The race to the bottom on price and the top on capability is so ferocious that you cannot build a sustainable competitive advantage here. You leverage this layer; you don't own it.

This is the brain. It's the code that gives the LLM a goal, a persistent memory, and the ability to reason, plan, and self-correct. It’s the difference between a calculator and a mathematician. Frameworks like CrewAI or LangChain are the early, primitive versions of this — the MS-DOS for agentic computing. They provide a structure for breaking down complex tasks into a sequence of steps that the LLM can process. Our internal systems are far more bespoke, designed specifically for the chaotic, data-rich environment of marketing. This layer is where the magic happens. It’s the orchestrator that decides, “Based on the drop in sales for SKU-123, I need to check our competitor’s pricing, analyse our past promotional data, draft three email variants, and schedule the best one for deployment.”

An agent is useless without tools and data. This layer gives the orchestrator its senses and its hands. It's a curated collection of APIs, databases, and access protocols. An agent tasked with optimising a Google Ads campaign needs access to the Ads API, a database of historical performance, and perhaps a tool like our own, Competable, to scrape and analyse competitor ad copy in real-time. Without these tools, the agent is just a brain in a jar — capable of thought, but incapable of action. The value here is in the aggregation and integration. Building proprietary data assets or exclusive API access is a powerful moat.

How do humans interact with these autonomous workers? The answer is not another 50-tab Chrome dashboard. The era of complex SaaS UI is ending. The new interface is natural language, coupled with high-level strategic oversight. You might interact via a simple text prompt, a voice command, or by setting objectives in a project management tool. The goal is to move from operator to manager. You’re not writing the emails; you’re approving the high-level campaign goal and budget suggested by your agent. Primitive versions of this new interaction model can be seen in tools that provide outputs directly, rather than processes. For example, our simple AI marketing calculator gives you a projection without forcing you to manipulate endless variables. The future is about defining outcomes, not micromanaging tasks.

The £100bn Question: Where's the Real Value?

So, where is the money in this new world? It's not where most VCs are looking. They’re funding yet another AI copywriting tool or a social media scheduler with an “AI-powered” caption generator. This is a fundamental misreading of the market.

That approach is about making existing workflows marginally more efficient. Agentic AI is about obliterating those workflows entirely. The real value, the £100bn prize, lies in vertical-specific, end-to-end automation of costly business problems. Take marketing budgets. The CMO Survey consistently finds that around 26% of marketing spend is wasted due to poor data, strategy, or execution. That’s tens of billions squandered in the UK alone. The value is not in a tool that helps a brand manager write a blog post 10% faster. The value is in an agent that claws back that 26% of wasted budget by autonomously managing and optimising performance marketing channels based on real-time market data.

Instead of building a horizontal tool for everyone, the winners will build deep, vertical agents for specific industries. An agent for fashion ecommerce that can manage the entire lifecycle of a flash sale. An agent for B2B SaaS that handles lead nurturing from webinar signup to sales-qualified-lead. These are not simple tools. They are complex systems deeply integrated into the business. This is what we focus on at our agency, and you can see more of our thinking on the future of marketing in our various essays and articles.