Which AI platform should I optimise for first?

The one your buyers use, not the largest. A firm selling to engineering teams has more at stake on Claude and Perplexity than on ChatGPT despite the size difference, and a business selling into large organisations should check Copilot first.

Why does my brand appear on one AI platform but not another?

Because they do not share an index or a set of preferences. Winning on one tells you close to nothing about your position on another, which is why a single blended visibility score removes the only information worth having.

Are the ChatGPT and Perplexity user numbers comparable?

No. Weekly active users, monthly active users and monthly queries are three different metrics, each chosen by the company reporting it. There is no independent audit of assistant usage. Use the figures for order of magnitude and nothing finer.

Why am I invisible in Microsoft Copilot?

Usually because of Bing rather than anything AI-specific. Copilot is grounded entirely in the Bing index, so a site indexed well in Google and poorly in Bing is absent there. Bing Webmaster Tools is free and checking it takes twenty minutes.

What is actually coming next in AI search?

Three things are already visible rather than predicted: assistants that complete tasks instead of answering, crawler access becoming a negotiation, and measurement moving from clicks to mentions. Paid placement and a single winning assistant are speculation.

02Module

The AI Search Landscape

Understanding the major players in AI search: ChatGPT, Claude, Perplexity, Gemini, Copilot, and more. How each platform works and why they matter for your brand.

Available3 lessons19 min

Five systems account for nearly all AI answer traffic worth optimising for: ChatGPT, Google AI Overviews and Gemini, Perplexity, Microsoft Copilot and Claude. They do not share an index or a set of preferences. In one large 2026 synthesis only about 11% of domains cited by ChatGPT were also cited by Perplexity, which is why optimising for all five at once means optimising for none.

This module is about a single mistake that costs more than any other in GEO: treating "AI" as one destination. The platforms do not share an index, a set of preferences, or a citation style, and in one large synthesis only about 11% of the domains cited by ChatGPT were also cited by Perplexity. Almost everything practical follows from taking that number seriously.

It covers who the five platforms actually are, how to read the usage figures they publish about themselves, how each one finds and cites information, and which claims about where this is all heading are supported by something you can check.

It is for anyone about to buy an AI visibility tool, brief an agency, or set a target. All three go wrong in the same way, by averaging across systems that disagree with each other.

If you read one lesson: How Each Platform Works. It carries the evidence and the measurement consequence.

Lessons

Questions this module answers

Which AI platform should I optimise for first?: The one your buyers use, not the largest. A firm selling to engineering teams has more at stake on Claude and Perplexity than on ChatGPT despite the size difference, and a business selling into large organisations should check Copilot first.; In fullThe Major AI Players
Can I optimise for all the AI platforms at once?: Not meaningfully. They differ in citation volume, source preference and freshness weighting, and in one large 2026 synthesis only about 11% of domains cited by ChatGPT were also cited by Perplexity. Optimising for all five means optimising for none.; In fullHow Each Platform Works
Why does my brand appear on one AI platform but not another?: Because they do not share an index or a set of preferences. Winning on one tells you close to nothing about your position on another, which is why a single blended visibility score removes the only information worth having.; In fullHow Each Platform Works
Are the ChatGPT and Perplexity user numbers comparable?: No. Weekly active users, monthly active users and monthly queries are three different metrics, each chosen by the company reporting it. There is no independent audit of assistant usage. Use the figures for order of magnitude and nothing finer.; In fullThe Major AI Players
Why am I invisible in Microsoft Copilot?: Usually because of Bing rather than anything AI-specific. Copilot is grounded entirely in the Bing index, so a site indexed well in Google and poorly in Bing is absent there. Bing Webmaster Tools is free and checking it takes twenty minutes.; In fullThe Major AI Players
What is actually coming next in AI search?: Three things are already visible rather than predicted: assistants that complete tasks instead of answering, crawler access becoming a negotiation, and measurement moving from clicks to mentions. Paid placement and a single winning assistant are speculation.; In fullWhere AI Search is Heading

Lessons

Questions this module answers

Which AI platform should I optimise for first?: The one your buyers use, not the largest. A firm selling to engineering teams has more at stake on Claude and Perplexity than on ChatGPT despite the size difference, and a business selling into large organisations should check Copilot first.; In fullThe Major AI Players
Can I optimise for all the AI platforms at once?: Not meaningfully. They differ in citation volume, source preference and freshness weighting, and in one large 2026 synthesis only about 11% of domains cited by ChatGPT were also cited by Perplexity. Optimising for all five means optimising for none.; In fullHow Each Platform Works
Why does my brand appear on one AI platform but not another?: Because they do not share an index or a set of preferences. Winning on one tells you close to nothing about your position on another, which is why a single blended visibility score removes the only information worth having.; In fullHow Each Platform Works
Are the ChatGPT and Perplexity user numbers comparable?: No. Weekly active users, monthly active users and monthly queries are three different metrics, each chosen by the company reporting it. There is no independent audit of assistant usage. Use the figures for order of magnitude and nothing finer.; In fullThe Major AI Players
Why am I invisible in Microsoft Copilot?: Usually because of Bing rather than anything AI-specific. Copilot is grounded entirely in the Bing index, so a site indexed well in Google and poorly in Bing is absent there. Bing Webmaster Tools is free and checking it takes twenty minutes.; In fullThe Major AI Players
What is actually coming next in AI search?: Three things are already visible rather than predicted: assistants that complete tasks instead of answering, crawler access becoming a negotiation, and measurement moving from clicks to mentions. Paid placement and a single winning assistant are speculation.; In fullWhere AI Search is Heading