Lead Source Attribution Automation — Domain-Based Mapping

Overview

When leads enter Salesforce through agency-managed landing pages or contact enrichment tools, the Lead Source field often defaults to the wrong value — typically the ad platform or enrichment tool rather than the agency responsible for the lead. This article documents the pattern for correcting that attribution automatically using a domain-based Salesforce automation.

The approach was first implemented for ^[1]'s ABM campaign, where leads arriving via the PaperTube.pro landing page were being attributed to "Google AdWords" or "Hunter.io" instead of "Asymmetric."

The Problem

Salesforce populates the Lead Source field using whatever signal arrives first — often the ad platform that drove the click (e.g., Google AdWords) or the enrichment tool used to source the contact (e.g., Hunter.io). When an agency manages a dedicated landing page or domain, inbound leads from that domain should be attributed to the agency, not the upstream traffic source.

Symptoms observed:
- Leads from PaperTube.pro showing Lead Source = "Google AdWords"
- ABM contacts loaded via Hunter.io showing Lead Source = "Hunter.io"
- Client unable to distinguish agency-sourced leads from self-sourced leads

The Solution

Deploy a Salesforce automation (Flow or Apex trigger) that watches the UTM Source or referrer URL on incoming leads and contacts, and overwrites the Lead Source field when a match is found.

Logic

IF Lead.UTM_Source contains "PaperTube.pro"  (wildcard match, any path)
  THEN Lead.Lead_Source = "Asymmetric"

IF Contact.Lead_Source = "Hunter.io"
  AND Contact is in ABM sequence
  THEN Contact.Lead_Source = "Asymmetric"

The domain wildcard (PaperTube.pro/*) ensures that any page on the managed domain — regardless of path or campaign — triggers the correct attribution.

Scope

• Object: Lead (for inbound form fills) and Contact (for loaded ABM contacts)
• Trigger: On insert and on update when UTM Source changes
• Field written: Lead_Source (standard picklist field; "Asymmetric" must exist as a picklist value)

Account-Level Attribution

By default, Salesforce does not expose a Lead Source field on the Account object — it exists only on Lead and Contact. To surface attribution at the account level:

1. Add a custom Account_Lead_Source__c field to the Account object.
2. Create an automation that syncs Contact.Lead_Source → Account.Account_Lead_Source__c when a contact is created or updated under that account.
3. Use the Contact as the authoritative source; the Account field is a read-through for reporting.

Note: The standard Lead-to-Contact conversion mapping does not automatically carry Lead Source to a custom Account field. The sync automation must be set up separately.

Picklist Requirements

Before deploying, confirm that "Asymmetric" (or your agency name) exists as a value in the Lead Source picklist. This is a global value set in Salesforce — adding it to Lead Source on the Lead object also makes it available on Contact.

To verify: Setup → Object Manager → Lead → Fields & Relationships → Lead Source → Edit

Reporting

Once attribution is corrected, create a Lead report filtered to Lead Source = Asymmetric to track agency-sourced pipeline. Because Lead and Contact are separate objects in Salesforce, two reports are typically needed:

These reports can be added to a shared ABM dashboard for client-facing visibility.

Scope gotcha: New reports default to "My Leads/Contacts" scope, which hides records owned by other users. Change the scope to "All Leads" / "All Contacts" (or "Organization") to see the full dataset. This was the cause of empty "Asymmetric Activity" reports observed during the PaperTube setup.

Implementation Notes

• The automation was built and deployed live during the ^[2] using an Apex-assisted approach via the existing ABM Apex class.
• The existing Apex sync class (which handles Pardot engagement data) was the natural place to add UTM-based attribution logic, since it already reads and writes contact/lead fields on each sync cycle.
• A backfill was run after deployment to retroactively update existing contacts whose Lead Source was set to Hunter.io.

Related

• ^[3]
• ^[4]
• ^[5]