AI search traffic visibility in GA4 requires explicit setup — by default, AI search referrals appear scattered across 'Direct' and 'Referral' channels and are easy to miss. The full setup: **Step 1: Identify AI referrer hostnames.** The major sources to track: - chat.openai.com (ChatGPT) - perplexity.ai (Perplexity) - gemini.google.com (Google Gemini) - claude.ai (Anthropic Claude) - copilot.microsoft.com (Microsoft Copilot) - you.com (You.com) - phind.com (Phind, popular for technical queries) - duckduckgo.com (with DuckAssist enabled) - brave.com/search (Brave Search Summarizer) **Step 2: Create a custom channel grouping in GA4.** Admin → Channel Groups → Custom Channel Group → Add new channel called 'AI Search' with conditions matching the referrer hostnames listed above. **Step 3: Create comparisons or segments for AI Search traffic.** Use the new channel in Reports to compare AI Search performance against other channels — engagement rate, conversion rate, average session duration, pages per session. **Step 4: Set up alerts.** Create custom alerts for AI Search traffic crossing thresholds (e.g., notify when AI Search traffic exceeds 5% of total weekly traffic) so you can respond to growth or sudden drops. **Step 5: Track AI Overview citation traffic separately.** AI Overview clicks within Google Search appear as regular Google organic traffic in GA4. To track AI Overview traffic specifically, look at Search Console for queries where impressions are high but click-through rates are unusually low (this often indicates AI Overview is intercepting clicks). **Important caveats for Canadian businesses:** AI search traffic volumes are still small in absolute terms for most sites — typically 1–5% of total traffic in 2026, growing to projected 10–15% by 2028. The qualitative value of AI search traffic often exceeds its quantitative weight: visitors arriving via AI search citations often have higher intent and convert at meaningfully better rates than equivalent traditional organic visitors. Do not under-invest in AI search optimization based on current low traffic share — the compounding curve is steep and businesses establishing citation patterns now have significant compounding advantages by 2027.