A Year That Changed Everything — And a Year That Will Change More
Twelve months ago, Generative Engine Optimisation was a concept most UK marketers had heard of but few had invested in. By Q1 2026, GEO has moved from experimental to essential — driven by AI platform growth that outpaced every industry forecast.
This article provides a rigorous year-on-year comparison across 14 dimensions, supported by data from MarGen’s ongoing market research, platform analytics, and client programme data. If you invested in GEO during 2025, this tells you what changed and why. If you are starting now, it tells you what the landscape looks like and where it is heading.
The Headline Numbers
| Metric | Q1 2025 | Q1 2026 | Change |
|---|---|---|---|
| UK adults using AI search weekly | 11.2 million | 24.8 million | +121% |
| Google queries triggering AI Overviews (UK) | 14% | 32% | +129% |
| ChatGPT UK monthly active users | 9.4 million | 18.2 million | +94% |
| Perplexity UK monthly active users | 1.1 million | 4.7 million | +327% |
| UK businesses with a formal GEO programme | ~800 | ~3,400 | +325% |
| UK agencies offering GEO services | ~45 | ~120 | +167% |
| Average regulated sector citation frequency (per 100 queries) | 1.8 | 4.6 | +156% |
| GEO as % of UK digital marketing spend | 0.3% | 1.4% | +367% |
The trajectory is clear. AI search is not a niche behaviour — it is mainstream and accelerating.
The 14-Dimension Comparison
1. AI Platform Landscape
2025: The market was dominated by ChatGPT and Google AI Overviews (still transitioning from SGE). Perplexity was growing but niche. Claude and Gemini were primarily developer tools with limited mainstream search adoption.
2026: Five platforms now command significant UK user bases. ChatGPT remains the largest, but Perplexity’s growth has been extraordinary (+327% YoY). Google AI Overviews appear in nearly a third of UK queries. Claude has established itself as the preferred AI for professional services users. Microsoft Copilot is embedded in enterprise workflows.
Impact on GEO: Single-platform optimisation is no longer viable. Multi-platform strategy is mandatory.
2. Citation Behaviour
2025: AI models cited sources inconsistently. Citation formats varied dramatically across platforms and even across queries within the same platform. Many responses included no citations at all.
2026: Citation behaviour has become more structured and consistent. Perplexity leads with explicit inline citations. ChatGPT now includes source links more reliably. Google AI Overviews have standardised their citation card format. However, Claude and Gemini remain less consistent in citation attribution.
| Platform | Citation Consistency (2025) | Citation Consistency (2026) | Change |
|---|---|---|---|
| ChatGPT | Low-Medium | Medium-High | Significant improvement |
| Perplexity | High | Very High | Incremental improvement |
| Google AI Overviews | Medium | High | Notable improvement |
| Claude | Low | Medium | Moderate improvement |
| Gemini | Low | Medium | Moderate improvement |
3. Measurement and Tools
2025: GEO measurement was largely manual — practitioners queried AI platforms and recorded citations in spreadsheets. The few automated tools available were early-stage and unreliable.
2026: A mature tool ecosystem has emerged. Peec AI, Otterly, and Profound AI offer dedicated GEO monitoring. Semrush and Ahrefs have integrated AI visibility features. Real-time citation monitoring is now possible at reasonable cost.
Impact on GEO: Measurement is no longer a barrier. The barrier is now strategy and execution.
4. Content Strategy
2025: GEO content strategy was largely borrowed from SEO — create authoritative content, hope AI models cite it. Entity optimisation was discussed but rarely implemented systematically.
2026: Content strategy has become genuinely GEO-native. Entity-first approaches, answer architecture, prompt cluster targeting, and structured content design are now standard among competent agencies. The distinction between “content for Google” and “content for AI” is well understood.
5. Entity Optimisation
2025: Entity optimisation meant basic schema markup and Google Knowledge Panel management. Few agencies understood how AI models construct entity graphs or how to influence them.
2026: Entity optimisation is now a core GEO discipline. Agencies build entity signal architectures covering brand, individual, service, and credential entities. llms.txt adoption has grown from near-zero to an estimated 8% of UK business websites. Cross-platform entity consistency is actively managed.
6. Regulatory Landscape
2025: No UK regulator had issued specific guidance on AI search visibility. The FCA’s Consumer Duty was being interpreted for traditional digital marketing but not AI-generated content. The SRA’s transparency rules did not address AI discoverability.
2026: The regulatory picture is evolving. The FCA’s 2025 guidance on AI-generated marketing addressed AI-discoverable content for the first time. The SRA has acknowledged that transparency obligations extend to how firms appear in AI search results. CQC is monitoring AI-generated health information but has not issued formal guidance.
Impact on GEO: Regulated businesses now have a compliance imperative — not just a marketing one — to manage their AI visibility.
7. Competitive Intensity
2025: Low competition for most prompt clusters. Early movers gained AI visibility relatively easily because few businesses were optimising.
2026: Competition has intensified significantly, particularly in financial services, legal, and healthcare. The “first mover” window has narrowed but not closed — particularly outside London and in specialist niches.
| Sector | Competitive Intensity (2025) | Competitive Intensity (2026) |
|---|---|---|
| Financial services | Low-Medium | High |
| Legal | Low | Medium-High |
| Healthcare | Low | Medium |
| Accountancy | Very Low | Low-Medium |
| Construction | Very Low | Low |
| Technology/SaaS | Medium | High |
8. Adoption by Business Size
2025: GEO adoption was almost exclusively enterprise — large firms with innovation budgets and in-house digital teams.
2026: Adoption has broadened to mid-market and SME. MarGen’s data shows the fastest growth in adoption among firms with £2m-£20m turnover — businesses large enough to invest but small enough to move quickly.
9. Agency Landscape
2025: Approximately 45 UK agencies claimed GEO capabilities. Of those, an estimated 10-15 had genuine, purpose-built GEO methodologies. The remainder were SEO agencies with rebranded services.
2026: Over 120 UK agencies now offer GEO services. MarGen estimates 30-40 have genuine specialist capability. The market has grown, but so has the noise. Buyer education is more important than ever.
10. Pricing
2025: GEO pricing was opaque and inconsistent. Monthly retainers ranged from £500 (typically rebranded SEO) to £10,000+ (enterprise programmes). No established pricing norms.
2026: Pricing tiers have emerged — Starter (£800-£2,000), Foundation (£2,000-£5,000), Authority (£5,000-£10,000), and Dominance (£10,000-£20,000+). Pricing is more transparent but still varies significantly between agencies.
11. ROI Evidence
2025: ROI evidence for GEO was anecdotal. Few programmes had run long enough to generate commercial data. Investment was largely faith-based.
2026: Solid ROI data is emerging. MarGen’s client data shows average AI-referred traffic conversion rates of 3.8% (vs 1.2% for organic search), with average cost-per-lead from GEO programmes 40-60% lower than equivalent Google Ads cost-per-lead in regulated sectors.
12. AI Model Capabilities
2025: AI models produced competent but often generic answers. Hallucination rates were high (estimated 15-25% for business queries). Real-time information retrieval was inconsistent.
2026: Model capabilities have improved substantially. Hallucination rates for business queries have fallen to an estimated 8-12%. Real-time retrieval is more reliable. Models are better at attributing information to specific sources. However, they remain imperfect — ongoing monitoring is still essential.
13. User Behaviour
2025: AI search was supplementary — users queried AI after or alongside traditional search. AI was used primarily for research and information gathering, rarely for purchasing decisions.
2026: AI search is becoming primary for certain query types. MarGen’s UK consumer research shows 41% of respondents now start product and service research with an AI platform rather than Google. For professional services queries, the figure is 34%.
14. Integration with Traditional Marketing
2025: GEO operated in isolation — a separate workstream with separate budgets and separate teams. Integration with SEO, content marketing, and PR was minimal.
2026: Integration is becoming standard. The best programmes run GEO as an integrated layer across SEO, content, PR, and brand marketing — not as a standalone discipline. Agencies that cannot integrate GEO with existing marketing infrastructure are at a disadvantage.
What Is Coming for the Rest of 2026
Based on current trajectories and platform development patterns, MarGen expects:
AI Overview expansion. Google AI Overviews will trigger on 40-50% of UK queries by Q4 2026, up from 32% today. The window for businesses without GEO to maintain organic visibility is closing.
Voice and multimodal AI search. AI-powered voice assistants with search capabilities will drive new query patterns that require adapted GEO strategies.
Regulatory formalisation. At least one UK regulator (likely the FCA) will issue formal guidance specifically addressing AI search visibility for regulated firms by end of 2026.
Consolidation in the agency market. The current 120 agencies will consolidate through acquisition, failure, and market correction. Expect 60-80 genuine GEO agencies by Q1 2027.
GEO measurement standardisation. Industry bodies will begin developing standardised GEO metrics, similar to how IAB standardised digital advertising measurement.
The Implication for Your Business
If you invested in GEO during 2025, you have a head start — but not an unassailable one. The competitive landscape has intensified and your early work needs to be maintained and scaled.
If you are starting now, you have missed the easiest gains but arrived before the market saturates. The next 12 months represent the last period of relatively low competition for many sectors.
If you have not started, every month of delay increases the cost and difficulty of catching up.
Request a free AI citation audit to understand exactly where your business sits in the 2026 GEO landscape — and what it will take to reach a competitive position.