Tools · Comparison · 5 min read

Claude, ChatGPT or Gemini for marketing: which and when.

Alessandro Iannuzzi
Alessandro Iannuzzi
Growth strategist, founder As Growth · Updated 21 October 2026
We run €27M+ of business infrastructure for our partners

By the end of this you know which to use for which task, and how many you actually need.

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Three wrenches of different shapes beside three matching bolts, each suited to its own
The short answer

For marketing there is no best model in the abstract, only the one suited to the task: models tend to differ on long coherent writing, web research, and integration with the tools you already use. The practical choice depends less on the model than on where your work lives: inside Google Workspace or Microsoft, integration matters more than any difference in quality.

"Which is best" is the question everybody asks and the one with no stable answer.

Models change every few months, and a ranking written today is stale by spring. What does not change is the criterion you choose by, and that is the part worth learning.

The criterion that does not age

As Growth credo

Do not pick the best model. Pick the one already living where you work.

The time lost copying text between a browser tab and your document exceeds any quality gap between two serious models. When your work lives in Google Docs, a model integrated there saves you more than a slightly better model elsewhere earns you.

How they differ, on real tasks

TaskWhat actually mattersHow to check
Long coherent writingholding the thread for 1,500 wordshave it write, then read the ending
Research with sourcesciting real pages, not plausible onesopen three links at random
Data analysisnot inventing absent numbershand it a file with a gap
Volume draftingcost per output, not peak quality20 variants, count the rejects
Team workintegration and permissionshow long a colleague takes

The column that counts is the third. Differences between models show up by trying them on your own material, not by reading comparisons: ten minutes on your case is worth more than ten articles like this one.

The test we run before adopting one

  1. NOIHand it an old piece of yours and ask for criticism — see whether it grasps context or repeats generalities
  2. NOIAsk for a figure from your sector with the source — then open it. This eliminates several
  3. AIHave it write 20 ad variants — count how many you would discard
  4. NOIGive it an incomplete brief — a useful model asks, a useless one invents
  5. NOILet a non-technical colleague use it — needing a course means nobody at the agency will

The fourth is the most informative of all, and almost nobody runs it. A model that confidently produces something anyway, from a brief full of holes, is more dangerous than one that stops and asks.

How many you actually need

One good one, used well, beats three used badly.

The temptation to subscribe to all of them is strong and expensive: €20-30 a month each, and multiplied across a year it becomes a real line. Paying for more than one makes sense only with a recurring task where one is clearly better, verified by you rather than read somewhere.

What almost always pays off instead is keeping the ability to switch: do not build the whole workflow around one model's quirks, because in six months the ranking will differ. The tools we use and what they cost are in the stack.

A multi-tool with every blade fanned open beside a single well-sharpened knife

What does not change, whichever you choose

Three things hold across all of them, and they decide whether the work comes out well.

The brief matters more than the model. A brief with context, audience, constraints and examples produces better output on any model than a thin brief does on the best one.

Numbers always get checked. Every model invents statistics with exactly the face it wears when reporting real ones. On a client site, one invented number is damage you cannot undo.

Final judgement stays human. Deciding a draft is publishable is an editorial call, and delegating it is exactly how AI slop gets made. What you can genuinely hand an agent is in the AI agents guide.

Frequently asked questions

What is the best AI for marketing?

There is no stable answer, because models change every few months and a ranking written today ages within a season. The criterion that does not age is different: pick the one integrated where you already work, because time lost copying text between tabs exceeds any quality gap between two serious models.

Is it worth subscribing to more than one AI model?

Rarely. They run €20-30 a month each and across a year that becomes a real line item. Paying for more than one makes sense only when you have a recurring task where one is clearly better, and you verified that on your own material rather than reading it in a comparison.

How do you test a model before adopting it?

With five tests on your own material: have it criticise an old piece of yours, ask for a figure from your sector with the source and then open it, have it write twenty variants and count the rejects, give it an incomplete brief, and let a non-technical colleague use it. The fourth is the most informative.

Why give a model an incomplete brief during testing?

Because it separates useful models from dangerous ones. A useful one stops and asks what is missing; one that confidently produces something anyway is filling gaps with plausible invention, and on real work that invention travels all the way to the client.

Can AI write the content for me?

It can write drafts, and quickly. It cannot decide a draft is publishable, which is an editorial judgement about a specific audience at a specific moment. When that decision gets delegated it shows, and that is exactly how AI slop gets made.

What matters more than which model you pick?

The brief. With context, audience, constraints and examples, any serious model produces better output than the best model does with a thin brief. Right behind it comes checking the numbers, because every model invents statistics with the same confidence it reports real ones.

Want to know which one suits your case?

Tell us what you need to produce and we will say what we would use. Seven questions, founders answer within 48 hours.

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Alessandro Iannuzzi
Alessandro Iannuzzi

Founder of As Growth, an AI-first growth partner. He runs growth and strategy across partner businesses: OroEtic, Giojello, Equity Plus and others. Apply if you want to work with us.

Published 21 October 2026 · Updated 21 October 2026