B2B Web Tracking Forensic Audit and Remediation

The Problem

The client had a history of tracking reliability problems, and Microsoft lead tracking was reported as failing even while leads, MQLs and SQLs were present in Salesforce. The account was considered strategically important, so inaccurate conversion signals directly undermined reporting confidence and paid-media optimization.

Approach & Architecture

Established GTM production version 464 as the immutable audit baseline and explicitly separated Published/Production, Current Workspace and Observed Behavior. Diagnosed both Microsoft custom-event tags, replaced the non-invoked function pattern with direct window.uetq.push() calls, and validated the resulting browser requests to Microsoft before publication. Created the missing Microsoft conversion goal for the Deepfake report and confirmed both custom events appeared in Microsoft UET Insights. Then instrumented HubSpot with a temporary diagnostic listener, proved onFormSubmitted behavior on both the main contact form and the Deepfake report form, and rewrote the central listener to use confirmed post-submission data while preserving existing downstream dataLayer event names.

HubSpot forms on identity.client.com emit hsFormCallback messages. B2B Hubspot Form Listener DC converts successful onFormSubmitted callbacks into the stable dataLayer contract hubspot-form-data plus hubspot-form-success, carrying form GUID, email and phone. Platform-specific GTM tags consume hubspot-form-success; Microsoft tags enqueue submit_lead_form or deepfake_era_download into UET, which sends requests to bat.bing.com/action/0. Microsoft conversion goals then match the UET event action names.

Key Decisions & Trade-offs

Hardest Part

The hardest diagnostic was proving that Microsoft tracking was failing despite GTM reporting the conversion tag as fired. Inspection of the tag code showed that it only defined uet_report_conversion() and never called it; replacing that with a direct UET queue push and then finding ea=submit_lead_form / ea=deepfake_era_download in actual bat.bing.com requests with HTTP 204 converted a suspected configuration problem into a proven root cause.

Technical Detail

Code

function uet_report_conversion() { window.uetq = window.uetq || []; window.uetq.push('event', 'submit_lead_form', {});
}

window.uetq = window.uetq || [];
window.uetq.push("event", "submit_lead_form", {});

window.uetq = window.uetq || [];
window.uetq.push("event", "deepfake_era_download", {});

window.addEventListener("message", function(event) { if ( event.data && event.data.type === "hsFormCallback" && event.data.eventName === "onFormSubmitted" ) { window.dataLayer.push({ event: "client-hubspot-submitted-debug", hubspot_event_data: event.data }); }
});

window.addEventListener("message", function(event) { if (!event.data || event.data.type !== "hsFormCallback" || event.data.eventName !== "onFormSubmitted") return; var values = event.data.data && event.data.data.submissionValues ? event.data.data.submissionValues : {}; var formData = []; for (var key in values) { if (Object.prototype.hasOwnProperty.call(values, key)) formData.push({ name: key, value: values[key] }); } var email = values.email || ""; var phone = values.phone || ""; var formGuid = event.data.id || (event.data.data && event.data.data.formGuid) || ""; window.dataLayer = window.dataLayer || []; window.dataLayer.push({ event: "hubspot-form-data", "hs-form-guid": formGuid, "hs-formData": formData }); if (email && phone) { window.dataLayer.push({ event: "hubspot-form-success", "hs-form-guid": formGuid, "hs-form-email": email, "hs-form-phone": phone }); }
});

Measured Results

The audit converted a vague 'Microsoft tracking is broken' report into a proven code-level root cause and validated browser-to-Microsoft transmission for both submit_lead_form and deepfake_era_download. Microsoft UET Insights then showed both event names, and the missing Deepfake conversion goal was created. The central HubSpot listener was also successfully regression-tested in Quick Preview using onFormSubmitted; the chat does not contain evidence that the final combined GTM changes were published to production.

Every figure above was recorded during the work itself. Where no number was measured, none is claimed.

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