diff --git a/metrics/amplitude.js b/metrics/amplitude.js
index 92c2c32..4487c29 100644
--- a/metrics/amplitude.js
+++ b/metrics/amplitude.js
@@ -180,7 +180,7 @@ module.exports = {
           }
         }
 
-        return pruneUnsetValues({
+        const properties = pruneUnsetValues({
           op: 'amplitudeEvent',
           event_type: `${eventGroup} - ${eventType}`,
           time: event.time,
@@ -197,6 +197,21 @@ module.exports = {
           event_properties: mapEventProperties(eventType, eventGroup, eventCategory, eventTarget, data),
           user_properties: mapUserProperties(eventGroup, eventCategory, data)
         });
+
+        if (! properties.user_properties.entrypoint) {
+          // If no entrypoint is specified, use the service name or client_id
+          // as the entrypoint to minimize occurrences of "entrypoint=none"
+          // results in Amplitude. service name is preferred because
+          // it's human readable.
+          // See https://github.com/mozilla/fxa-content-server/issues/6757
+          if (properties.event_properties.service && properties.event_properties.service !== 'undefined_oauth') {
+            properties.user_properties.entrypoint = properties.event_properties.service;
+          } else if (properties.event_properties.oauth_client_id) {
+            properties.user_properties.entrypoint = properties.event_properties.oauth_client_id;
+          }
+        }
+
+        return properties;
       }
     };
 
diff --git a/test/metrics/amplitude.js b/test/metrics/amplitude.js
index bd1345c..db867b8 100644
--- a/test/metrics/amplitude.js
+++ b/test/metrics/amplitude.js
@@ -294,7 +294,7 @@ describe('metrics/amplitude:', () => {
       });
     });
 
-    describe('transform an event with undefined service:', () => {
+    describe('transform an event with service=unknown client_id:', () => {
       let result;
 
       before(() => {
@@ -306,7 +306,29 @@ describe('metrics/amplitude:', () => {
           oauth_client_id: 'gribble',
           service: 'undefined_oauth'
         });
-        assert.deepEqual(result.user_properties, { '$append': { fxa_services_used: 'undefined_oauth' } });
+        assert.deepEqual(result.user_properties, {
+          '$append': { fxa_services_used: 'undefined_oauth' },
+          entrypoint: 'gribble'
+        });
+      });
+    });
+
+    describe('transform an event with service=known client_id:', () => {
+      let result;
+
+      before(() => {
+        result = transform({ type: 'wibble.blee' }, { service: 'foo' });
+      });
+
+      it('returned the correct event data', () => {
+        assert.deepEqual(result.event_properties, {
+          oauth_client_id: 'foo',
+          service: 'bar'
+        });
+        assert.deepEqual(result.user_properties, {
+          '$append': { fxa_services_used: 'bar' },
+          entrypoint: 'bar'
+        });
       });
     });
 
@@ -319,7 +341,10 @@ describe('metrics/amplitude:', () => {
 
       it('returned the correct event data', () => {
         assert.deepEqual(result.event_properties, { service: 'sync' });
-        assert.deepEqual(result.user_properties, { '$append': { fxa_services_used: 'sync' } });
+        assert.deepEqual(result.user_properties, {
+          '$append': { fxa_services_used: 'sync' },
+          entrypoint: 'sync'
+        });
       });
     });