11 August 2026

ChatGPT isn’t replacing Google. Yet.

In summary

• What: OpenAI has reportedly told investors advertising could become a US$100 billion global business by 2030, while eMarketer forecasts the entire US standalone chatbot ad market will reach US$5.41 billion by then.
• Why: Building a large audience isn’t the same as building a large advertising business. ChatGPT still needs to prove it can deliver the scale, measurement and performance advertisers expect.
• The challenge: Google has decades of search behaviour, advertiser investment and an ecosystem that allows it to introduce generative AI without asking users to change their habits.
• What marketers should do: Test ChatGPT as an emerging advertising channel, but pay close attention to changing search behaviour, particularly among younger audiences.

A huge audience doesn’t guarantee a huge ad business

ChatGPT has already achieved something most technology companies never will: it changed how millions of people use the internet.

However, turning that behaviour into a US$100 billion advertising business may be much harder.

In April OpenAI reportedly told investors that advertising could become a US$100 billion global business by 2030. But last month, Adweek reported a very different outlook from eMarketer: the entire US standalone chatbot advertising market, including ChatGPT, Microsoft Copilot, Google AI Mode and Amazon’s Alexa for Shopping, will reach just US$5.41 billion by then.

The figures aren’t directly comparable. One is OpenAI’s global ambition; the other is a forecast for the broader US chatbot advertising category. But the gap points to a much bigger challenge.

For OpenAI to build an advertising business anywhere near that scale, it won’t be enough for people to use ChatGPT. Advertisers need to spend there too.

And that means competing with one of the most entrenched habits on the internet: Google.

Google doesn’t need users to switch

Google’s advantage isn’t simply the quality of its search engine or the size of its advertising business. It’s that searching with Google has become a behaviour people barely think about.

People Google things.

That habit is reinforced by an ecosystem spanning Search, Chrome, Gmail, YouTube, Maps, Android and the Google account sitting behind them.

There’s also trust. Decades of using Google to find information have built familiarity with the platform and confidence in what happens when you search. That trust, combined with habit, gives Google an advantage that a newer platform can’t replicate overnight.

Google’s response to generative AI has strengthened that position. Rather than asking users to leave Search and adopt an entirely new product, it has introduced AI Overviews, AI Mode and Gemini across experiences people already use.

That matters because Google doesn’t necessarily need to convince people to change their behaviour to adopt generative AI. It can bring AI to them.

OpenAI faces the opposite challenge. It needs to give people a reason to break an established behaviour.

There’s an interesting precedent here.

When Google launched Google+, it wasn’t enough to build a social network capable of competing with Facebook. Facebook already had the users, their friends and the behaviour that kept them coming back. Convincing people to move somewhere else was much harder than simply building an alternative.

This time, Google is the incumbent.

Attention doesn’t automatically become advertising revenue

ChatGPT has built enormous consumer awareness and usage. But having an audience and building an advertising ecosystem are two different things.

OpenAI reportedly expects its advertising business to generate US$2.5 billion this year. eMarketer, meanwhile, estimates the entire US standalone chatbot advertising market will generate less than US$1 billion.

Again, the forecasts cover different geographic scopes, so they shouldn’t be treated as a direct comparison. But they demonstrate just how uncertain the economics of chatbot advertising remain.

For advertisers, the decision is simpler.

They will move meaningful budget to ChatGPT if it delivers meaningful results.

That means competitive costs, scalable audiences, reliable measurement and, ultimately, business outcomes.

If an advertiser can spend the same dollar through Google and generate a better return, there’s little reason to move significant budget simply because ChatGPT is a new and fast-growing platform.

In Australia, ChatGPT advertising is still an emerging channel, with advertisers beginning to test where it fits within the broader media mix. Until the platform can consistently demonstrate incremental value, larger investment is likely to remain cautious.

Could ChatGPT become the next Microsoft Ads?

Not overtaking Google doesn’t mean ChatGPT advertising has failed.

There is another possible outcome: it becomes a valuable secondary advertising channel.

Microsoft Ads provides a useful comparison. For many advertisers, it offers incremental reach and can deliver strong performance, but Google remains the platform where the majority of search investment begins.

ChatGPT could initially occupy a similar position.

Advertisers establish their core activity across Google and Meta, then allocate additional budget to ChatGPT where its audience and performance justify the investment.

That’s still a significant advertising business. It’s just very different from becoming a dominant competitor to Google.

For OpenAI to move higher up the media plan, it will need to demonstrate that ChatGPT offers something advertisers can’t already get elsewhere, whether that’s a different audience, stronger intent, better performance or entirely new advertising experiences.

The next generation could change the equation

There is one part of the equation that could challenge Google’s advantage: younger users.

In Australia, that shift may already be starting. Ipsos iris found 72% of Australians aged 14–24 used an AI website or app in April 2025, with younger users spending almost twice as much time with AI platforms as the average user.

Adobe research also found 42% of Australian Gen Z regularly use AI assistants, while 78% are either using them more or intend to do so.

That doesn’t mean Gen Z has abandoned Google. But it does suggest the habit of turning to AI assistants for information and discovery is becoming increasingly established among younger Australians.

Trust matters here too. It’s easier to build familiarity and trust with a platform while behaviours are still forming. If younger audiences grow up using ChatGPT and other AI assistants as part of how they search, research and make decisions, those platforms have an opportunity to become something they instinctively turn to rather than something they have to learn to adopt later.

Platform shifts don’t always happen because existing users suddenly abandon the products they know. They can happen because the next generation grows up with different ones.

If younger consumers increasingly begin their discovery journeys through ChatGPT and other AI assistants rather than automatically opening Google, today’s emerging behaviour could eventually become tomorrow’s default.

Google isn’t standing still either.

AI Overviews, AI Mode and Gemini give younger users access to generative AI without requiring them to leave Google’s ecosystem. That makes the battle less about traditional search versus AI and more about which company becomes the default starting point for discovery.

The important question isn’t simply whether ChatGPT can take advertising revenue from Google today.

It’s whether “ask ChatGPT” can eventually become as instinctive as “Google it”.

Search isn’t disappearing. It’s changing.

For marketers, this isn’t a binary Google versus ChatGPT battle anyway.

The distinction between search engines and AI assistants is already becoming less clear.

Google is becoming more generative. ChatGPT is becoming more search-like. AI assistants including Claude and Gemini are increasingly influencing how people research products, compare options, find information and make decisions.

That shift also explains the growing interest in GEO, or generative engine optimisation.

Brands are starting to ask the same question about AI platforms that they have spent decades asking about search: how do we make sure we’re visible when someone is looking for something we offer?

That may prove more immediately important for marketers than trying to predict which platform eventually wins the advertising battle.

The real battle is over behaviour

ChatGPT doesn’t need to replace Google to become an important advertising platform.

But becoming important and building a US$100 billion advertising business are very different ambitions.

Google enters this fight with decades of trust, an established advertising ecosystem and an enormous distribution advantage. OpenAI has built one of the fastest-growing technology products in history, but now it needs to prove that user attention can translate into advertiser results at scale.

For marketers, the question isn’t simply which platform wins. It’s where people choose to start their next search.

Google owns today’s search habit. The real battle is over who owns the next one.

Louder recommendations

• Treat ChatGPT as an emerging channel, not a Google replacement: Test advertising opportunities where they make sense, but don’t move significant budget based on audience growth or AI momentum alone.
• Measure incremental value: ChatGPT needs to earn its place in the media mix. Compare performance against existing channels and understand whether it is reaching new audiences or simply shifting conversions between platforms.
• Watch younger audiences closely: The bigger threat to Google’s position may not be an immediate migration of existing users. It could be a generation that develops different discovery habits from the beginning.
• Think beyond paid media: Generative AI is already changing discovery regardless of how quickly chatbot advertising grows. Brands should understand how they appear across ChatGPT, Gemini, AI Mode and other generative experiences.
• Don’t separate GEO from SEO: Traditional search and generative discovery are increasingly part of the same customer journey. Brands should consider how their SEO strategy supports visibility across both search engines and AI-powered experiences.

Get in touch

Get in touch with Louder to discuss how AI search, emerging advertising channels and changing discovery behaviours could impact your media strategy.

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