Most Agencies Are Using ChatGPT Wrong — Here's Why It's Costing Them Clients
A few months ago, I sat across from a marketing agency owner who looked completely burnt out. His shoulders slumped, coffee in hand, and the frustration practically radiated off him. He’d just lost one of his longest-standing clients — a well-paying account he’d held for over a year. On paper, everything in their latest campaign looked solid: the visuals were sharp, the funnel logic checked out, and the audience targeting was spot-on.
So what went wrong?
The answer blindsided him: the content. More specifically, the email copy. It wasn’t offensive. It wasn’t off-brand. It was just... forgettable. Bland. Robotic. The kind of thing you’d scroll past without a second thought. The client said it “didn’t sound like them anymore.” That it felt like it had been written by someone who didn’t really understand their business. But the reality was worse — it hadn’t been written by someone at all. It was written by ChatGPT. He showed me the exact prompt he’d used:
“Write me a high-converting email for an ecommerce brand.”
That was it. That was the entire input behind a $5,000/month client’s campaign. Now don’t get me wrong — ChatGPT is a powerful tool. But like any tool, it’s only as good as the person using it. If you hand it a vague prompt, it gives you vague results. The AI did exactly what it was told — the output was grammatically correct and even sounded “marketing-y.” But it lacked depth. No understanding of the audience. No brand tone. No customer objections being handled. No compelling reason to act now.
It was AI-generated copy that read like it was copied-and-pasted from a template graveyard.
And the cost? A lost client, and a wake-up call for the agency.
Michael smith - 14.06.2025
The Illusion of AI Mastery
Everywhere you look right now, agencies are shouting about their “AI-powered workflows.”
They post screenshots of ChatGPT chats. They brag about saving hours on content creation. They tell clients they’re “leveraging advanced tools” to stay ahead of the game. But step behind the curtain — and you’ll often find a different story. In reality, most of these agencies are not using AI strategically. They’re rushing. They’re guessing. They’re plugging in vague prompts and hoping the output magically lands. It’s not innovation — it’s copywriting roulette.
You’ll see prompts like:
“Write a Facebook ad for a gym.”
“Give me 5 Instagram captions about skincare.”
“Generate blog ideas for a law firm.”
That’s not marketing. That’s a coin toss.
And sure — the AI gives them something back. But what they get is cookie-cutter copy. The same recycled language. The same tired hooks. It might look okay at a glance, but it reads like filler. No positioning. No brand voice. No understanding of the audience. It’s content that says, “We didn’t have time to care.” And clients can feel it. They might not say it outright, but they’ll quietly start questioning the value. Engagement drops. Campaigns underperform. Trust erodes. Then one day, they walk. The sad truth? These agencies think they’re saving time — but they’re actually burning their brand. Because when everyone uses the same tools the same lazy way, everyone sounds the same.
What sets great agencies apart isn’t if they use AI — it’s how well they do it. And that all starts with better prompts.
Why Clients Can Tell When It’s AI-Generated
Clients are getting smarter. Sharper. More aware. They can smell AI-generated content a mile off — even if they don’t know it’s AI. They just know something’s off. It lacks nuance. It lacks warmth. It lacks them. One agency owner told me about a long-term client — someone they'd worked with for over a year. Solid relationship, good results. Then one day, the feedback came in like a slap in the face:
“It just didn’t sound like us anymore. The voice was… off.”
That one comment cost them a $5,000/month retainer. And here’s the kicker: nothing else had changed. The offer was the same. The funnel was working. But the content? It suddenly felt robotic. Generic. Rushed. Why? They’d started using ChatGPT without a system. Just tossing in prompts like:
“Write an email campaign for a product launch.”
And the result was exactly what you’d expect: content that sounded fine… but felt wrong.
It didn’t hit the emotional tone. It didn’t reflect the brand’s values. It didn’t answer objections or build trust. It was output without empathy. What that agency didn’t realise is that clients are listening for authenticity.
They want to hear their voice — not a machine’s. And if you don’t deliver that? They won’t argue. They won’t complain. They’ll just leave.
In today’s world, where every agency is “using AI,” the difference between keeping a client and losing one often comes down to how human your content feels — and that starts with the right prompts.
What went wrong? The prompts were lazy. The inputs were vague. And the outputs didn’t reflect the brand’s tone, customer objections, or core offer.
Real-World Fix: Upgrading the Prompt Game
When I started STACKD, it wasn’t to sell prompts. It was to fix broken workflows. We tested over 1000 variations of prompts in real agency environments. Different tones, goals, industries. And the pattern was obvious: Generic prompts = generic results. Expert prompts = standout content, faster. Example: Instead of: "Write a Facebook ad for a personal trainer. We tested:
"Write a short-form Facebook ad for a 32-year-old female personal trainer based in Manchester who helps busy mums lose weight without strict diets. The ad should use emotional storytelling, mention real client results, and include a call-to-action to download her free 3-day meal plan."
Same tool. Different prompt. Night-and-day results. READ FOR YOUR SELF >
"Write a Facebook ad for a personal trainer"
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"Write a short-form Facebook ad for a 32-year-old female personal trainer based in Manchester who helps busy mums lose weight without strict diets. The ad should use emotional storytelling, mention real client results, and include a call-to-action to download her free 3-day meal plan"
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The STACKD Approach to AI Content
We don’t just give agencies prompt templates. We give them systems:
Frameworks to generate content in a brand’s voice
Prompts tailored for high-converting hooks, body copy, CTAs
Pre-tested scripts for email sequences, social posts, landing pages
Our packs are built with real data, shaped by live campaigns, and updated as platforms evolve.
Why This Matters Now
AI isn’t going away. But clients won’t tolerate bad content just because it came from a machine. They want speed, scale, and quality. You can’t offer all three unless your AI inputs are engineered with intention.
That’s why STACKD exists.
If you’re an agency owner relying on AI to scale your output — you owe it to yourself to use it properly.
Want to see how expert prompts change the game?
[Download our free AI Prompt Sampler Pack for Agencies] — and see how STACKD helps agencies create smarter, faster, better content.