In this article, we break down the three buzz-words everyone keeps hearing—AIO, LLMO, and GEO—and show how they fit into “SEO for the generative-AI age.”

Because some terms catch on overseas while others are coined in Japan, there’s still no universal naming convention. For consistency, we’ll use the three expressions that appear most often in global discussions of generative-AI-driven SEO.

A Brief Recap of Generative-AI Trends

1. The Rise of ChatGPT

ChatGPT burst onto the scene when OpenAI released the model on 30 November 2022, and it rocketed to one million users in just five days. By January 2023 it had already crossed the 100-million-user mark—the fastest adoption curve of any consumer product to date. Momentum has only accelerated since then, with weekly active users topping 400 million by February 2025.

https://www.theguardian.com/technology/2023/feb/02/chatgpt-100-million-users-open-ai-fastest-growing-app

https://www.reuters.com/technology/artificial-intelligence/openais-weekly-active-users-surpass-400-million-2025-02-20/

2. Search Traffic vs. Generative-AI Traffic

In March 2024, Gartner published its report “Gartner Predicts Search Engine Volume Will Drop 25% by 2026, Due to AI Chatbots and Other Virtual Agents,” forecasting that traditional search traffic will decline by 25 percent by 2026.

On the English-language sites we monitor with Google Analytics at CoDigital, more than 3 percent of all sessions already originate from large language models such as ChatGPT, Gemini, and Perplexity.

While the overall search market is still expanding, we can no longer rule out a scenario in which Google-driven traffic levels off—or even begins to fall.

Meanwhile, we've also encountered some challenges with STUDIO, the website-building and publishing platform we use internally. Certain AI agents—such as Genspark and Manus—struggle to accurately read and extract information from sites built on this platform.

To address this issue, we are now seriously considering migrating to a self-hosted WordPress environment, which would offer greater control and compatibility with AI agents.

3. The Advancement of Generative AI Services and AI Agents

Back in 2022 and 2023, generative AI services were often criticized for producing outdated or inaccurate information. Fast forward to May 2025, and many of these tools have now surpassed human capabilities in a number of areas.

Personally, I subscribe to the paid versions of ChatGPT, Perplexity, and Gemini, and actively use and test a variety of services—especially AI agents that can autonomously complete complex tasks.

In fact, the post below was created using both Gemini and Manus.

Amid these developments, it's becoming increasingly clear that significant shifts are underway in the world of SEO and online customer acquisition.

The AI-Powered Search Experience on Google

In the English-language post published on May 21, 2025, titled “Top ways to ensure your content performs well in Google's AI experiences on Search” Google emphasized not only its long-standing philosophy of creating “original, high-value, human-first content”—but also highlighted several additional factors that are becoming increasingly important in how content is evaluated within the AI-powered search experience.

Ensure structured data aligns with visible content
If you want to be eligible for rich results, your markup must accurately reflect the on-page content, following Google’s guidelines and passing validation checks.

Go beyond text to support multimodal experiences
Provide high-quality images and videos, and keep your Merchant Center and business profile information up to date. Prepare for new search behaviors, such as image-based queries.

Prioritize the overall value of a visit over clicks alone
Traffic from AI Overviews tends to show higher engagement and longer dwell times. Measure outcomes across multiple dimensions—such as sales, sign-ups, and inquiries.

Evolve your strategy alongside user behavior
Search is constantly changing. With the rise of AI-driven experiences, users are asking more complex questions. AI Overviews surface a wide range of source links, creating new visibility opportunities for your content.

New search paradigms are arriving fast: a wider range of input formats (image, voice, video), sharper personalization with emotion recognition, results that update in real time, and—further down the road—hands-free, brain-wave-driven querying.

Because Google now weighs the overall value of each visit, success will hinge less on raw clicks and more on on-site engagement: time on page, interactions, conversions, and other deeper signals.

As generative-AI services craft hyper-personalized answers, users will pose ever more complex follow-up questions, making finely tailored information more valuable than ever.

In short, winning the future means optimizing not only the search experience but also everything that happens after the click. Mastering AIO, LLMO, and GEO is essential to stay visible—and useful—throughout this AI-driven journey.

Why Do We Need AIO, LLMO, and GEO?

For years Japan’s search landscape was effectively a duopoly: Google and Yahoo! Japan (which simply uses Google’s algorithm). Ranking well in Google was almost synonymous with winning organic traffic, so “SEO” essentially meant “Google SEO.”

That comfort zone is disappearing fast.

Search Is No Longer Just “Type, Click, Compare”

The spread of generative-AI tools—ChatGPT, Google Gemini, and many others—has begun to rewrite the search journey itself. Instead of typing keywords and comparing a list of links, users increasingly ask a question and receive an instant, summarized answer from an AI.

Services such as Perplexity, Claude, Grok, and Genspark keep multiplying, so the information-gathering arena is expanding well beyond traditional search engines.

Real-world data:
On the English-language sites we monitor at CoDigital, more than 3 percent of all sessions already originate from LLMs (ChatGPT, Gemini, Perplexity, etc.).

If you spot referrers like these in Google Analytics, you’re already receiving traffic from an LLM:

chatgpt.com / referral
gemini.google.com / referral
perplexity.ai / referral
copilot.microsoft.com / referral
chat.deepseek.com / referral
poe.com / referral

Because this share is clearly growing, forward-looking optimization is essential.

AIO, LLMO, GEO—What Do They Mean?

What Exactly Is AIO?

AI Optimization covers all activities that make your information easy for AI systems—search engines, LLMs, internal chatbots—to ingest, understand and rank favorably. LLMO and GEO are both sub-disciplines within AIO.

What Is LLMO?

Large Language Model Optimization focuses on maximizing the chances that LLMs such as ChatGPT, Gemini, or Perplexity learn and inference your content. In concrete terms, it’s the content-design and exposure strategy that gets your brand baked into the model’s knowledge base and cited in its outputs.

(In AI jargon, “inference” is the stage where a trained model applies its knowledge to new data and produces an answer.)

What Is GEO?

Generative Engine Optimization ensures that, when AI search features perform live web crawling (e.g., ChatGPT’s search mode, Gemini, Perplexity, Genspark), your pages are selected as citation cards or reference links inside the generated response.

LLMO vs. GEO—A Quick Analogy

Friend: “Got any good restaurant recommendations near my place?”
You:

1. Suggest a spot you’ve visited.

2. Or mention a famous local place you’ve heard about.
     → Information that’s already in your head → LLMO (teaching the model).

3. If nothing comes to mind, you Google / Tabelog it, find a well-reviewed option, and then recommend it.
     → Fetching new info on the fly → GEO (letting the engine search).

Key Takeaways

• AIO (AI Optimization)
  Every initiative that helps any AI system recognize, understand, and positively assess your brand or content.

• LLMO (Large Language Model Optimization)
  The slice of AIO devoted to making sure LLMs learn and quote your content accurately.

• GEO (Generative Engine Optimization)
  Tactics that secure citation cards or reference links to your site inside AI-generated answers (e.g., Google AI Overviews, Perplexity).

At CoDigital, we help organizations deploy generative-AI tools and build end-to-end AIO strategies—including both LLMO and GEO. If you’d like to explore what that looks like for your business, feel free to reach out through our contact form.

https://codigital.co.jp/en/contact