{
  "id": "measurement.referrer-segments",
  "protocol": "measurement",
  "layer": "foundation",
  "role": "merchant",
  "status": "recommended",
  "title": "Segment AI assistant traffic (Option A built-in channel, or Option B custom group)",
  "description": "For AI assistant feed links, choose the medium yourself. Option A: utm_medium=ai-assistant lands in GA4's built-in AI Assistant default channel with no setup (support.google.com/analytics/answer/9756891). Option B: your own medium (for example ai) plus a GA4 custom channel group placed above Referral; without that group the traffic lands in Unassigned. Untagged visits from assistants only show up through the referrer. chatgpt.com, gemini.google.com, perplexity.ai, copilot.microsoft.com and claude.ai are the assistants' public hosts and their appearance as referrers is observed or assumed, not documented.",
  "goal": "See AI assistant traffic as one channel: either GA4's built-in AI Assistant channel (Option A) or your own custom channel group (Option B), with referrer matching as a backup.",
  "note": "Recommendation only. The site does not pick the medium for the shop. Apps and privacy settings often strip referrers, so referrer matching undercounts. Review the host list against your own referral report. GA4 default channel definitions: support.google.com/analytics/answer/9756891.",
  "how_to_implement": {
    "steps": [
      "Pick Option A (utm_medium=ai-assistant) or Option B (own medium, e.g. ai).",
      "Option A: no custom channel group needed; confirm sessions land in GA4's AI Assistant default channel.",
      "Option B: in GA4, create a custom channel group with a channel named AI assistants. Rule: Medium exactly matches your chosen value OR Session source matches regex chatgpt\\.com|gemini\\.google\\.com|perplexity\\.ai|copilot\\.microsoft\\.com|claude\\.ai. Place AI assistants above Referral.",
      "Optionally keep a separate segment on the same source regex for explorations."
    ]
  },
  "resources": [
    {
      "label": "GA4 default channel group",
      "url": "https://support.google.com/analytics/answer/9756891",
      "type": "docs",
      "publisher": "Google"
    },
    {
      "label": "Simon Vreeman: GA4 UTM convention and builder",
      "url": "https://vreeman.com/utm",
      "type": "docs",
      "publisher": "Simon Vreeman (convention)"
    }
  ],
  "audit": {
    "method": "analytics",
    "automatable": false,
    "human": "If Option A: GA4 default AI Assistant channel shows tagged sessions. If Option B: custom channel group shows AI assistants sessions for your medium and matching referrers. Compare with tagged feed traffic."
  },
  "how_to_verify": "If Option A: GA4 default AI Assistant channel shows tagged sessions. If Option B: custom channel group shows AI assistants sessions for your medium and matching referrers. Compare with tagged feed traffic.",
  "artifacts": [
    "{ai_medium}",
    "ai-assistant",
    "referrer",
    "custom channel group"
  ],
  "depends_on": [
    "measurement.utm.feed-links"
  ],
  "status_note": "Recommendation only. The site does not pick the medium for the shop. Apps and privacy settings often strip referrers, so referrer matching undercounts. Review the host list against your own referral report. GA4 default channel definitions: support.google.com/analytics/answer/9756891.",
  "verified": false,
  "slug": "measurement-referrer-segments",
  "category": "foundation",
  "url": "https://vreeman.ai/commerce/checklist#measurement.referrer-segments",
  "updated": "2026-10-12",
  "sources": [
    {
      "label": "GA4 default channel group",
      "url": "https://support.google.com/analytics/answer/9756891",
      "type": "docs",
      "publisher": "Google"
    },
    {
      "label": "Simon Vreeman: GA4 UTM convention and builder",
      "url": "https://vreeman.com/utm",
      "type": "docs",
      "publisher": "Simon Vreeman (convention)"
    }
  ],
  "related_slugs": [
    "measurement-utm-feed-links"
  ]
}