Reference
How SourceTag Categorises Visitors
When someone visits your site, SourceTag categorises them into a marketing channel based on their UTM parameters, click IDs, and referrer. This channel (along with source, campaign, and other data) is stored in the cookie and populated into your forms.
Why utm_medium is the primary signal
Channel detection is built around utm_medium, not utm_source or utm_campaign. The medium tells you how the traffic arrived (paid click, email, social post), while the source tells you where it came from (Google, Facebook, Mailchimp). A single source can send traffic via multiple channels (e.g. Google sends both paid and organic), so medium is the more reliable signal for categorisation.
utm_source and utm_campaign are used as filters to narrow a match after detection, not as primary detectors.
The 11 default channels
SourceTag comes with 11 pre-configured channels based on industry-standard channel groupings. They’re evaluated top to bottom. The first match wins.
| Priority | Channel | How it matches |
|---|---|---|
| 1 | utm_medium is email, e-mail, email-marketing, newsletter, or broadcast | |
| 2 | Affiliates | utm_medium is affiliate, affiliates, or partner |
| 3 | Paid Social | utm_medium is paidsocial, paid-social, paid_social, social-paid, cpc, ppc, or paid. Also matches if has fbclid or ttclid click ID. Must also have utm_source matching a social platform (facebook, fb, meta, instagram, ig, linkedin, twitter, x, tiktok, snapchat, pinterest, reddit, threads, youtube) |
| 4 | Paid Search | utm_medium is cpc, ppc, paid, paidsearch, paid-search, paid_search, search-ads, adwords, or adword. Also matches if has gclid, msclkid, gbraid, or wbraid click ID |
| 5 | Display | utm_medium is display, banner, cpm, interstitial, expandable, or rich-media |
| 6 | Paid Video | utm_medium is video, paid-video, paid_video, pre-roll, preroll, or instream |
| 7 | Other Campaigns | Has UTM parameters but didn’t match any channel above |
| 8 | Organic Social | Referrer is a recognised social network (70+ domains). Also matches if utm_medium is social, organic-social, or organic_social |
| 9 | Organic Search | Referrer is a recognised search engine (80+ domains including AI search engines). Also matches if utm_source is chatgpt, openai, perplexity, claude, gemini, copilot, meta.ai, phind, kagi, or andi |
| 10 | Referral | Has an external referrer that didn’t match any channel above |
| 11 | Direct | No referrer and no UTM parameters |
How matching works: detection vs filters
Each channel has conditions. There are two types:
Detection conditions (utm_medium, has_click_id, referrer_domain) use OR logic. If ANY one of these matches, the channel is a candidate.
Filter conditions (utm_source, utm_campaign) use AND logic. If specified, these must ALSO match on top of the detection. Filters narrow the match after detection - they never trigger a match on their own.
Example: Paid Social detects on utm_medium = cpc (among others) but also filters on utm_source matching a specific social platform name (facebook, fb, meta, instagram, ig, linkedin, twitter, x, tiktok, snapchat, pinterest, reddit, threads, youtube). So utm_medium=cpc&utm_source=google does NOT match Paid Social (fails the source filter), but utm_medium=cpc&utm_source=facebook does.
Why priority order matters
Paid Social (priority 3) is checked before Paid Search (priority 4) because it’s more specific. Both channels detect on cpc as a medium, but Paid Social adds the extra requirement that utm_source is a social platform. Without this ordering, utm_medium=cpc&utm_source=facebook would incorrectly match Paid Search first.
Email sits at priority 1 because email traffic always has a distinctive utm_medium value - there’s no ambiguity, so it’s matched early and removed from consideration.
Other Campaigns (priority 7) sits above the organic and referral channels as a catch-all for UTM-tagged traffic that didn’t match a specific paid channel. This prevents UTM-tagged visits from falling through to Organic Social or Organic Search based on their referrer.
More specific channels should always be higher priority than broader ones.
Fallback channels
The last four channels (Organic Social, Organic Search, Referral, Direct) are primarily referrer-based or catch-all:
- Organic Social: Referrer from a social network domain, or
utm_mediumissocial/organic-social/organic_social - Organic Search: Traffic from a recognised search engine (including AI search engines and answer engines)
- Referral: Visitor has an external referrer but didn’t match any channel above
- Direct: No referrer and no UTMs
Customising channels
All channel rules can be customised in the SourceTag dashboard. You can:
- Reorder channels to change priority
- Disable channels you don’t need (toggle off)
- Extend default channels by adding extra utm_medium values, utm_source values, or referrer domains
- Add custom channels with your own name and conditions
For example, you might add a “Partner Referrals” channel that matches utm_medium=partner and place it above Affiliates in the priority list.
See Configure Channel Rules for step-by-step instructions.
Smart fields
Each channel has 4 smart fields that contain the most relevant data for that channel type. These are the core fields most users work with, and you can customise the mapping for each channel.
| Channel | Smart Field 1 | Smart Field 2 | Smart Field 3 | Smart Field 4 |
|---|---|---|---|---|
| utm_source (e.g. mailchimp) | utm_campaign | utm_term | utm_content | |
| Affiliates | utm_source | utm_campaign | utm_term | utm_content |
| Paid Social | utm_source (e.g. facebook) | utm_campaign | utm_term | utm_content |
| Paid Search | utm_source (e.g. google) | utm_campaign | utm_term (keyword) | utm_content |
| Display | utm_source | utm_campaign | utm_term | utm_content |
| Paid Video | utm_source | utm_campaign | utm_term | utm_content |
| Other Campaigns | utm_source | utm_campaign | utm_term | utm_content |
| Organic Social | Referrer domain (e.g. Facebook) | utm_campaign | utm_term | utm_content |
| Organic Search | Referrer domain (e.g. Google) | Referrer URL | utm_term | utm_content |
| Referral | Referrer domain | Referrer URL | - | - |
| Direct | - | - | - | - |
These defaults can be customised per channel in the channel editor. Each dropdown shows all available options with “(Default)” next to the recommended setting.
When a detail value is empty (e.g. no utm_term was present), the form field shows (not set) rather than being left blank. This makes it clear in your CRM that the field was captured but had no value, rather than the field being missing entirely.
What else gets captured
Beyond the smart fields, SourceTag also captures raw UTM values, click IDs, landing pages, visitor metadata, and custom parameters. All available as optional extended field groups you can toggle on or off.
See Captured Fields for the full list.
Doesn't answer your question or need more help? Get in touch.