diff --git a/website/api/controllers/save-questionnaire-progress.js b/website/api/controllers/save-questionnaire-progress.js
index d2106c9c20aa..5cf77ba3cf81 100644
--- a/website/api/controllers/save-questionnaire-progress.js
+++ b/website/api/controllers/save-questionnaire-progress.js
@@ -203,6 +203,14 @@ module.exports = {
     }
     // Only update CRM records if the user's psychological stage changes.
     if(psychologicalStage !== userRecord.psychologicalStage) {
+      let psychologicalStageChangeReason = 'Website - Organic start flow'; // Default psystageChangeReason to "Website - Organic start flow"
+      if(this.req.session.adAttributionString && this.req.session.visitedSiteFromAdAt) {
+        let thirtyMinutesAgoAt = Date.now() - (1000 * 60 * 30);
+        // If this user visited the website from an ad, set the psychologicalStageChangeReason to be the adCampaignId stored in their session.
+        if(this.req.session.visitedSiteFromAdAt > thirtyMinutesAgoAt) {
+          psychologicalStageChangeReason = this.req.session.adAttributionString;
+        }
+      }
       // Update the psychologicalStageLastChangedAt timestamp if the user's psychological stage
       psychologicalStageLastChangedAt = Date.now();
       sails.helpers.salesforce.updateOrCreateContactAndAccount.with({
@@ -212,6 +220,7 @@ module.exports = {
         primaryBuyingSituation: primaryBuyingSituation === 'eo-security' ? 'Endpoint operations - Security' : primaryBuyingSituation === 'eo-it' ? 'Endpoint operations - IT' : primaryBuyingSituation === 'mdm' ? 'Device management (MDM)' : primaryBuyingSituation === 'vm' ? 'Vulnerability management' : undefined,
         organization: this.req.me.organization,
         psychologicalStage,
+        psychologicalStageChangeReason,
         getStartedResponses: questionnaireProgressAsAFormattedString,
         contactSource: 'Website - Sign up',
       }).exec((err)=>{
diff --git a/website/api/helpers/salesforce/update-or-create-contact-and-account.js b/website/api/helpers/salesforce/update-or-create-contact-and-account.js
index 208e48f40644..2ee68f09599b 100644
--- a/website/api/helpers/salesforce/update-or-create-contact-and-account.js
+++ b/website/api/helpers/salesforce/update-or-create-contact-and-account.js
@@ -30,6 +30,10 @@ module.exports = {
         '6 - Has team buy-in'
       ]
     },
+    psychologicalStageChangeReason: {
+      type: 'string',
+      example: 'Website - Organic start flow'
+    },
     contactSource: {
       type: 'string',
       isIn: [
@@ -56,7 +60,7 @@ module.exports = {
   },
 
 
-  fn: async function ({emailAddress, linkedinUrl, firstName, lastName, organization, primaryBuyingSituation, psychologicalStage, contactSource, description, getStartedResponses}) {
+  fn: async function ({emailAddress, linkedinUrl, firstName, lastName, organization, primaryBuyingSituation, psychologicalStage, psychologicalStageChangeReason, contactSource, description, getStartedResponses}) {
     // Return undefined if we're not running in a production environment.
     if(sails.config.environment !== 'production') {
       sails.log.verbose('Skipping Salesforce integration...');
@@ -106,6 +110,9 @@ module.exports = {
     if(description) {
       valuesToSet.Description = description;
     }
+    if(psychologicalStageChangeReason) {
+      valuesToSet.Psystage_change_reason__c = psychologicalStageChangeReason;// eslint-disable-line camelcase
+    }
 
     let existingContactRecord;
     // Search for an existing Contact record using the provided email address or linkedIn profile URL.
diff --git a/website/api/hooks/custom/index.js b/website/api/hooks/custom/index.js
index 26e59b108971..d2bd549ddb96 100644
--- a/website/api/hooks/custom/index.js
+++ b/website/api/hooks/custom/index.js
@@ -147,6 +147,17 @@ will be disabled and/or hidden in the UI.
               res.locals.me = undefined;
             }//fi
 
+            // Check for query parameters set by ad clicks.
+            // This is used to track the reason behind a psychological stage change.
+            // If the user performs any action that causes a stage change
+            // within 30 minutes of visiting the website from an ad, their psychological
+            // stage change will be attributed to the ad campaign that brought them here.
+            if(req.param('utm_source') && req.param('creative_id') && req.param('campaign_id')){
+              req.session.adAttributionString = `${req.param('utm_source')} ads - ${req.param('campaign_id')} - ${_.trim(req.param('creative_id'), '?')}`;// Trim questionmarks from the end of creative_id parameters.
+              // Example adAttributionString: Linkedin - 1245983829 - 41u3985237
+              req.session.visitedSiteFromAdAt = Date.now();
+            }
+
             // Check for website personalization parameter, and if valid, absorb it in the session.
             // (This makes the experience simpler and less confusing for people, prioritizing showing things that matter for them)
             // [?] https://en.wikipedia.org/wiki/UTM_parameters