Paid
Organic
Why now
AI assistants have become the first stop for research. That makes the conversation itself a place to be seen, and since 2026 it is one you can buy into.
1.2 billion people use ChatGPT every week. They ask long, specific questions: which is best for, what should I compare, what can I get for under £1,500. Those are buying questions.
ChatGPT Ads are live in the UK with self-serve buying, CPC and conversion bidding, and OpenAI’s Pixel and Conversions API. OpenAI says the product passed a $1bn annualised run rate in under 200 days. Early channels reward the advertisers who learn them first.
In August 2026, AI-assistant traffic to UK retail sites converted 20% better than other traffic, according to Adobe. Being in the conversation, paid or organic, now affects revenue.
What’s included
From campaign strategy and setup to targeting, creative, tracking and reporting, we manage every part of your ChatGPT advertising, drawing on our paid media, SEO and AI search teams.
Whether ChatGPT ads fit your category, and where to start.
Outcome: a clear test, wait or GEO-first call
Telling OpenAI which conversations your ads belong in.
Measured on relevance and click-through rate
Ads written to follow an answer, not interrupt it.
Measured on click-through and conversion rate
For ecommerce, the right products with prices attached.
Measured on return on ad spend by product
So bidding optimises to sales and enquiries, not clicks.
Checked against tracked versus actual sales
Visitors arrive mid-comparison. The page should finish it.
Measured on conversion rate
CPC and conversion-optimised bidding, managed every week.
Measured on cost per acquisition
ChatGPT reported next to Google and Meta, on the same measures.
Reported on the sales and enquiries it produced
Every campaign includes
Results
ChatGPT Ads are new; AI search is not. These are published GEO results from Castle clients, plus how we run paid tests while the channel matures.
A Liverpool claimant law firm. Seven years of SEO let them switch off Google Ads; in 2026 we extended it into AI search, and ChatGPT now names HNK for CICA questions in Liverpool.
The private patient service of The Clatterbridge Cancer Centre NHS Trust. Consultant-led content, entity clean-up and an accessible WCAG 2.1 AA site, extended into AI search.
ChatGPT Ads only reached UK advertisers in 2026, so nobody has long-run results yet. Each first campaign we run is a controlled test: does it add new customers, and at what cost against Google Search? We will publish results, with their periods, once they mean something. Until then, read our complete guide to ChatGPT ads.
Client reviews
…the results have been outstanding. They’ve completely turned around our online performance — Google Ads are running more efficiently than ever, Meta campaigns are consistently profitable, and our Shopify sales have seen real, measurable growth month after month.
I honestly can't say how good everyone is at Castle, they can't do enough for you and the work and numbers they produce out of this world. If I could leave 10 stars I would
…Smashing targets & 24/7 support which is a big bonus for us can’t thank them enough. Connor who’s trying different strategies & believe me they bring in the results!
A really great team who fully engaged with our enterprise and brought us rapidly into a whole different level of positive and sustained engagement with our target audience. Very very pleased to be working with them. Brilliant communicators. They've made a huge difference.
The whole team at Castle International are an absolute asset to any business that needs a positive boost in their marketing strategy. Expertise, knowledge, patience and a friendly helpful attitude, aiming to give you a bespoke service throughout.
Our business has benefited massively by Castle and their team of creative experts. It is a wonderful company that is always working to achieve the best for you. They have a wealth of knowledge and offer outstanding marketing solutions always ensuring they deliver on their promise
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Explainer
ChatGPT ads are OpenAI’s advertising product: sponsored placements that appear in ChatGPT conversations, below the answer, when what someone is asking matches what you sell.
They are shown to users on the Free and Go plans and are chosen mainly by the context and intent of the conversation, rather than the keyword matching you find in Google Ads. Ads sit apart from ChatGPT’s response and are clearly labelled as sponsored.
Because people use ChatGPT to research, compare and shortlist, ads can reach them from the first question right through to the final decision.
OpenAI began testing ads in the US in February 2026 and has since launched them in the United Kingdom, where businesses can now buy through its self-serve Ads Manager.
How it works
Ads appear alongside conversations, only where relevant, rather than interrupting the flow of the answer. Castle’s job is the steps either side of the placement: the context that triggers it and the page and tracking that turn it into a customer.
Someone asks ChatGPT to recommend, compare or explain.
ChatGPT reads the intent behind the whole conversation, not a single keyword.
ChatGPT answers. Ads never change what it says.
A relevant ad appears below the answer, clearly labelled Sponsored.
The visitor lands mid-comparison, on a page built to finish it.
Pixel and Conversions API report the sale or enquiry back, so bidding learns.
Targeting & audience
Context and intent, not keyword lists. Ads reach people on ChatGPT’s free and low-cost plans while they explore, research and evaluate options before committing.
| ChatGPT plan | Ads | What it means |
|---|---|---|
| Free | Ads shown | The largest group of users, and where most everyday research happens. |
| Go | Ads shown | OpenAI’s low-cost plan. Also shown ads. |
| Plus | Ad-free | Paid plan, ad-free. |
| Pro | Ad-free | Paid plan, ad-free. |
| Business | Ad-free | Workplace plan, ad-free. |
| Enterprise | Ad-free | Workplace plan, ad-free. |
| Edu | Ad-free | Education plan, ad-free. |
Logged-in adults only. Source: OpenAI, “Testing ads in ChatGPT” and the OpenAI Help Centre, as of October 2026.
Brands whose customers research, ask for recommendations and compare before deciding. The longer and more considered the decision, the more useful a well-placed ad becomes.
Not for health, mental health or politics. OpenAI does not show ads near these conversations. For clinics and healthcare brands, the way into ChatGPT is organic visibility through GEO.
Paid + organic AI visibility
An ad buys the slot below the answer. GEO earns a mention inside it. Customers see both, often in the same conversation, so Castle plans them together from one piece of research.
Guaranteed presence in the conversations you choose, from launch day. Controlled by budget, context hints and bids, and measured to the sale.
The work that makes ads match also makes content get cited.
Castle GEO result · HNK Solicitors
A Liverpool claimant law firm, after a full GEO programme on top of years of SEO. ChatGPT accounted for 37 of the citations in August 2026.
AI-assistant traffic is still small, roughly 167 sessions a month (GA4), as the case study itself cautions. It is evidence of traction, not a forecast. Read the HNK case study.
Castle GEO result · Clatterbridge Private Clinic
12 citationsin AI answers for North West private cancer care questions. Health is a topic where ChatGPT shows no ads at all, so earned visibility is the only way into those conversations. Read the case study.
The research
The audience is large, UK shoppers are already using it, and the visitors it sends convert. The paid channel is new, so the evidence is early and we label it that way.
people use ChatGPT every week, according to OpenAI’s latest published figure.
OpenAI · 5 Oct 2026year-on-year growth in AI-assistant referral traffic to UK retail sites in August 2026.
Adobe · UK · Sep 2026better conversion from AI-referred traffic than other traffic to UK retail sites in August 2026.
Adobe · UK · Sep 2026UK visits to ChatGPT in January to August 2025, up from 368m in the same months of 2024.
Ofcom · Online Nation · Dec 2025Share of UK adults, 2026 surveys
Early advertiser signals (US, selected by OpenAI). WeightWatchers’ cost per acquisition on ChatGPT Ads was 15.3% below its blended paid-search benchmark; 93% of Portland Leather’s ChatGPT ad visitors were new to the brand; 67% of Dose’s incremental purchases came from new customers. These are case studies OpenAI chose to publish (5 Oct 2026), so treat them as signals rather than benchmarks.
Sources: OpenAI, “Building advertising for the way people use AI” (1.2bn weekly users; early advertiser results), 5 Oct 2026; OpenAI, “Testing ads in ChatGPT”, 2026; OpenAI Help Centre, “Ads in ChatGPT”, Sept 2026; Adobe UK report via Retail Technology Innovation Hub, 23 Sept 2026 (+149%, 20%, 37%); Idealo survey via IT Brief UK, 6 Aug 2026 (46%, 19%); Ofcom, Online Nation 2025, 10 Dec 2025 (1.8bn UK visits, 2025 data). ChatGPT Ads change roughly monthly; details on this page are as of October 2026.
Readiness check
Eight quick questions. Your score and a tailored next step update as you answer.
Do your customers research or compare options before they buy?
Do they ask detailed questions, like “which is best for…” or “what should I look for…”?
Is your category outside health, mental health and politics?
Do you sell to adults, with an advertising and billing entity in the UK?
Do you have landing pages that answer comparison questions clearly?
Is conversion tracking in place, recording sales or enquiries reliably?
Could you fund an 8–12 week test without needing it to pay back in month one?
Do you already have Google Ads or SEO data on what your customers search for?
Your readiness score
Answer the questions to see your score.
We weigh how considered your purchase is, whether customers ask ChatGPT the right questions, eligibility, landing pages, tracking and budget.
What to do next
Indicative only. Each answer scores Yes 2, Partly 1, No 0, averaged across the questions you answer. Ad eligibility rules are OpenAI’s as of October 2026. A free readiness review replaces this with a look at your own category, tracking and pages.
Why Castle
ChatGPT Ads are self-serve, so anyone can switch them on. Making them pay needs the context research, landing pages, tracking and AI search work to sit with one team.
| Feature | Castle | Typical PPC agency | Self-serve, in-house |
|---|---|---|---|
| Paid ChatGPT Ads and organic GEO run by the same team | Yes | No | No |
| Context hints built from real customer-question research | Yes | Sometimes | No |
| OpenAI Pixel and Conversions API set up and verified | Yes | Sometimes | DIY |
| Landing pages designed and built in-house | Yes | No | No |
| Judged against Google Ads on the same measures | Yes | Sometimes | No |
| Google Partner and Meta Business Partner | Yes | Sometimes | No |
| Honest advice when the answer is “not yet” | Yes | Not always | n/a |
| Contract terms | 30-day rolling | 6–12 months | Staff time |
Comparison reflects how Castle works and common market practice; it is not a review of any named provider.
The team
Castle’s ChatGPT ads work sits with the same people who run our Google and Meta accounts and our GEO programmes. The context research, the landing page and the tracking fix happen in one building, not across three suppliers.
Further reading
The complete guide to ChatGPT ads (2026)Every so often, a new advertising platform arrives that genuinely changes the game. Google did it in 2000. Facebook did it in 2007. TikTok did it in 2020…Read article
ChatGPT Business Ranking Requires These 10 Essential TacticsThe process begins when users ask ChatGPT to identify the top accountant operating in Manchester. 1. The system decides if it should perform web searches or…Read article
Answer Engine Optimisation Explained: How to Get Cited by AI AssistantsWhat process do AI assistants use to select their citation sources? The platforms demonstrate a uniform behaviour which enables the creation of a reliable…Read article
Why paid ads and GEO now work as one system, not two strategiesHow paid ads and GEO now work together in 2026, and why integrated marketing strategies help brands improve visibility across search, AI platforms, and…Read article
What Is AI Search Optimisation? A Practical Guide for UK BusinessesAI search optimisation enables businesses to achieve direct question responses from AI systems which include ChatGPT and Google’s AI Overviews and…Read article
AEO, GEO and AI SEO: The 2026 Glossary of AI Search TerminologyAnswer engine optimisation (AEO), generative engine optimisation (GEO) and AI SEO are overlapping terms for making a brand visible in AI-generated search…Read articleRelated services
One Liverpool team runs every channel, so adding a service means one plan and one report, not another agency.
Buy the intentGoogle AdsSearch, Shopping, Performance Max and YouTube, managed on cost per sale.Explore the service→
How customers will searchAI SEOVisibility in Google and in the AI assistants your buyers now ask first.Explore the service→
Shape how AI describes youGEOShape how ChatGPT, Gemini and Google’s AI describe your business.Explore the service→
Outrank your competitorsSEOTechnical SEO, content and links that compound into enquiries.Explore the service→Questions
Yes. OpenAI has launched ChatGPT Ads in the United Kingdom, and as of October 2026 UK businesses can buy through its self-serve Ads Manager, provided the advertising and billing entity is based in an available country. Castle launches, manages and optimises ChatGPT campaigns for UK brands.
Ads are matched to the context and intent of a conversation rather than exact keywords, using the conversation itself, your ad and landing page, the context hints you supply and your targeting. They appear below ChatGPT’s answer, separate from it and clearly labelled Sponsored, so users can always tell them apart from the response.
Logged-in adults on the Free and Go plans. Paid users on Plus, Pro, Business, Enterprise and Edu remain ad-free, and ads are not shown to under-18s.
No. OpenAI keeps advertising separate from ChatGPT’s responses, and advertisers never see people’s chats. Being named inside the answer itself is earned through organic AI visibility, which is what our GEO work does.
Not in the traditional sense. Targeting is built on conversational context and intent rather than keyword lists, so campaigns are set up around the topics and questions your customers bring to ChatGPT, described through context hints. Location targeting and custom audiences are also available.
OpenAI does not publish rate cards, and buying has moved from CPM to cost-per-click and conversion-optimised bidding. Trade press reported a minimum commitment of $200,000 at the January 2026 beta, since removed, and US CPMs of around $25 with suggested CPC bids of $3 to $5 by spring 2026. Treat those as reported US figures rather than UK prices. We recommend a defined test budget sized to your cost per acquisition, which we model with you before you commit.
Do not plan on it. OpenAI scaled back Instant Checkout, its in-chat purchase feature, in March 2026 and is moving towards merchant-owned checkout, with ChatGPT focused on discovery and comparison. In practice a ChatGPT ad sends people to your site, which is why landing pages and tracking matter so much.
Any brand whose customers research before they buy: B2B SaaS, professional services, legal, education, travel, finance, retail and ecommerce, luxury, technology, recruitment and property. The exceptions are health, mental health and politics, where OpenAI does not show ads; there, GEO is the way into ChatGPT.
They are different rather than strictly better. Google captures people searching with clear intent; ChatGPT reaches them while they research and compare, using contextual matching instead of keyword bidding. We run ChatGPT as a complement to paid search and judge it against Google on cost per acquisition and new-customer share.
With the OpenAI Pixel and Conversions API reporting sales and enquiries back to Ads Manager, checked against GA4 and your own sales data. We report cost per acquisition, return on ad spend and the share of new customers, next to your Google and Meta results, and we work on 30-day rolling terms.
Free readiness review
Book a call. We will look at your category, tracking and landing pages, map the questions your customers ask ChatGPT, and tell you whether to test ads now, start with GEO, or wait.
