AEO Saigon
Fundamentals

AI Search vs Google Search: What Is the Difference and How Should You Optimize?

Table of contents

In 2023, nobody in the Vietnamese marketing industry was talking about AEO. In 2024, ChatGPT surpassed 100 million users in Southeast Asia, and the first question on many business owners' lips became "Hey Siri..." or "ChatGPT, tell me..." instead of opening Google.

In 2026, the question is no longer "does AI search matter" — the question is "how many customers am I losing by not optimizing for AI search?"

To answer that, you need to understand the core differences between the two systems.

CriteriaGoogle SearchAI Search (ChatGPT/Perplexity/Gemini)
How it worksIndex → Ranking → Display linksRetrieve → Synthesize → Generate answer
Results returnedList of links (10 results/page)Synthesized answer + 3–5 citations
FreshnessReal-time index, continuously updatedKnowledge cutoff + web search (slower)
Ranking factorsBacklinks, authority, on-page SEORelevance, clarity, structured data, citations
User intentKeyword matchingUnderstands semantics and context
User experienceClick a link, read, go back, click againRead the answer, ask a follow-up
Click-throughRequires a click to readRead directly in the interface
Best suited forNavigational, transactional queriesInformational, advisory queries

These two systems do not compete directly — they serve two different types of needs.

Data from user behavior studies shows a clear shift:

  • 2023: AI search accounts for less than 5% of total queries, primarily tech-savvy users
  • 2024: ChatGPT surpasses 300 million active users globally; Perplexity reaches 100M/month
  • 2025: Google AI Overviews appear on 60%+ of search results in the US; organic CTR drops by an average of 15–20% for informational industries
  • 2026: AI search becomes the primary channel for advisory questions in Vietnam across B2B, finance, healthcare, and legal sectors

The most important point: Google itself is AI-ifying. Google's AI Overviews are essentially AI search embedded inside Google — and they also need structured data and answer-first content to cite correctly.

Query typeGoogle SearchAI Search
Finding a specific website★★★★★★★
Online shopping★★★★★★★★
Breaking news★★★★★★★★
Product comparisons★★★★★★★★★
"What should I do?" questions★★★★★★★★
Explaining concepts★★★★★★★★
Advisory/choosing★★★★★★★
Step-by-step guides★★★★★★★★
Finding local places★★★★★★★★
Academic research★★★★★★★★

Practical conclusion: If your customers typically ask advisory and comparison questions — AI search is where they are heading. If customers search transactionally (buy now, place an order, find a location) — Google remains the primary channel.

Ranking factors: SEO vs AEO — similarities and differences

What they share (80%)

  • High-quality content that matches intent
  • Domain authority and trustworthiness
  • Page speed and Core Web Vitals
  • Mobile-friendly
  • HTTPS and security
  • Backlinks from reputable sources
  • E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness)

What differs (20%)

FactorSEO prioritizesAEO prioritizes
Keyword densityImportantLess important
Structured dataHelpfulNear-mandatory
Answer box formatOptionalCore requirement
FAQ sectionGood for featured snippetsRequired
Backlink quantityHighly importantModerately important
Author credibilityHelpfulCritically important (YMYL)
Content depthLong > shortIn-depth + clear answer
Citation mentionsLittle impactHighly important

Budget allocation by industry

IndustrySEOAEOReason
B2B Tech / SaaS40%60%Customers ask AI before making decisions
Law / Finance / Healthcare50%50%YMYL needs both; AI search growing fast
E-commerce / Retail70%30%Google Shopping still strong; transactional queries
F&B / Local Business60%40%Google Maps is important; but local AI is growing
Education / E-learning45%55%Educational advisory questions are very common on AI
Real estate50%50%Both channels are strong
Interior design / Construction55%45%Pricing and material questions popular on AI

Reference ratios for Vietnamese SMEs in 2026; adjust based on specific circumstances.

Adding the AEO layer — no need to rewrite from scratch

What many businesses do not realize: you do not need to delete your old SEO content to do AEO. Add an "AEO layer" on top of existing SEO content:

Step 1 — Answer box Add to the top of each article (right after the h1 heading) a 150–200 word paragraph that directly answers the question in the title. No preamble, no "In this article we will...". Answer immediately.

Step 2 — FAQ section Add 5–7 frequently asked questions at the end of the article with FAQPage schema. This is where AI looks for answers to related queries.

Step 3 — Schema markup If the article does not yet have Article schema — add it. If it already does — check that author, dateModified, and publisher are all complete.

Step 4 — Update dateModified Update dateModified every time you make edits. AI (especially for YMYL content) prioritizes freshness.

Measuring AI visibility — a simple tracking system

SEO has Google Search Console for tracking. AEO does not yet have an equivalent official tool, but you can build your own measurement system:

MetricHow to measureFrequency
Citation rateAsk ChatGPT/Perplexity/Gemini 20 key questions, count % that cite youMonthly
Share of voiceCompare your citation rate vs 3 main competitorsQuarterly
New sourcesCheck which questions cite a competitor instead of youMonthly
AI referral trafficGoogle Analytics — filter referrals from perplexity.ai, chat.openai.comMonthly
Brand mentionsGoogle Alerts for company name + "AI" or "ChatGPT"Weekly

Dual-optimization checklist — SEO and AEO together

  • Article title contains the main keyword (SEO) + natural question form (AEO)
  • Opening paragraph directly answers the question in 150 words (AEO)
  • Article content is sufficiently in-depth, minimum 1000 words (SEO + AEO)
  • Article schema with author, datePublished, dateModified (AEO)
  • FAQPage schema with 5+ questions (AEO)
  • Internal links to related pillar pages (SEO)
  • Images with descriptive alt text (SEO)
  • Page speed under 3 seconds (SEO + AEO)
  • Mobile-friendly (SEO + AEO)
  • Author bio and credentials clearly visible (AEO — YMYL)

The right strategy is not choosing SEO or AEO — it is building a solid SEO foundation, then adding an AEO layer to optimize for both search channels. With 80% of factors in common, the effort is not doubled — but the reach can double when both Google and AI start recommending you to customers.

Frequently asked questions

Will AI Search replace Google Search?

In the next 2–3 years — not entirely. Google still processes 8+ billion queries per day (2025). But the balance is shifting: Gen Z and Millennial users are using AI for more complex, advisory-style questions. Google is also AI-ifying itself with AI Overviews. The better question is: 'In my industry, at what rate are customers switching to AI search?' The answer varies by industry — B2B tech is much higher than grocery shopping.

Does optimizing for AI Search conflict with SEO?

No — on the contrary, they support each other. 80% of good AEO factors are also good SEO: high-quality content, structured data, fast page load, domain authority. The main difference: AEO prioritizes answer-first format and schema markup; SEO prioritizes keyword density and backlinks. A website that works well for both: long, in-depth content (SEO) + a clear answer box at the top of the article (AEO) + complete schema (AEO).

How do AI Search and Google Search process queries differently?

3 core differences: (1) Results: Google returns a list of links → AI returns a synthesized answer + citations; (2) Freshness: Google indexes in real-time → AI models have a knowledge cutoff (ChatGPT 4o: Apr 2024), AI with search is updated but more slowly; (3) Intent: Google matches keywords → AI understands intent more naturally. User behavior also differs: Google search → click multiple links → compare; AI search → one long answer → follow-up questions.

How do I know if my industry is already being affected by AI search?

3 signals to check: (1) Google Search Console — compare CTR over the past 6 months against the same period last year; if impressions are up but CTR is down — AI Overviews are eating your traffic; (2) Ask directly — ask ChatGPT/Perplexity the 5 questions your customers ask most often; if AI answers without citing you — that is an opportunity; (3) Ask new customers — 'how did you find us?' if more and more people say 'ChatGPT recommended you' — it is time to invest in AEO.

What ratio should I split my budget between SEO and AEO?

It depends on your industry and stage. General principles for Vietnamese SMEs in 2026: (1) B2B tech/SaaS — 40% SEO, 60% AEO; (2) Professional services (law, finance, healthcare) — 50/50; (3) E-commerce/retail — 70% SEO, 30% AEO (Google Shopping is still strong; transactional queries); (4) F&B/local business — 60% SEO/local, 40% AEO. If you are starting from zero — build a solid SEO foundation first (6 months), then add an AEO layer on top.

AEO Saigon

An Answer Engine Optimization agency in Ho Chi Minh City — helping business websites get cited by AI. About AEO Saigon →

Want your website to be cited by AI like this?

Free Audit