--- a/dom/media/MediaRecorder.cpp
+++ b/dom/media/MediaRecorder.cpp
@@ -1194,16 +1194,18 @@ MediaRecorder::Start(const Optional<int3
     timeSlice = aTimeSlice.Value();
   }
   MediaRecorderReporter::AddMediaRecorder(this);
   mState = RecordingState::Recording;
   // Start a session.
   mSessions.AppendElement();
   mSessions.LastElement() = new Session(this, timeSlice);
   mSessions.LastElement()->Start();
+  mStartTime = TimeStamp::Now();
+  Telemetry::ScalarAdd(Telemetry::ScalarID::MEDIARECORDER_RECORDING_COUNT, 1);
 }
 
 void
 MediaRecorder::Stop(ErrorResult& aResult)
 {
   LOG(LogLevel::Debug, ("MediaRecorder.Stop %p", this));
   MediaRecorderReporter::RemoveMediaRecorder(this);
   if (mState == RecordingState::Inactive) {
@@ -1569,16 +1571,22 @@ MediaRecorder::StopForSessionDestruction
 {
   LOG(LogLevel::Debug, ("MediaRecorder.StopForSessionDestruction %p", this));
   MediaRecorderReporter::RemoveMediaRecorder(this);
   // We do not perform a mState != RecordingState::Recording) check here as
   // we may already be inactive due to ForceInactive().
   mState = RecordingState::Inactive;
   MOZ_ASSERT(mSessions.Length() > 0);
   mSessions.LastElement()->Stop();
+  // This is a coarse calculation and does not reflect the duration of the
+  // final recording for reasons such as pauses. However it allows us an idea
+  // of how long people are running their recorders for.
+  TimeDuration timeDelta = TimeStamp::Now() - mStartTime;
+  Telemetry::Accumulate(Telemetry::MEDIA_RECORDER_RECORDING_DURATION,
+                        timeDelta.ToSeconds());
 }
 
 void
 MediaRecorder::InitializeDomExceptions()
 {
   mSecurityDomException = DOMException::Create(NS_ERROR_DOM_SECURITY_ERR);
   mUnknownDomException = DOMException::Create(NS_ERROR_DOM_UNKNOWN_ERR);
 }

--- a/dom/media/MediaRecorder.h
+++ b/dom/media/MediaRecorder.h
@@ -162,16 +162,18 @@ protected:
 
   // It specifies the container format as well as the audio and video capture formats.
   nsString mMimeType;
 
   uint32_t mAudioBitsPerSecond;
   uint32_t mVideoBitsPerSecond;
   uint32_t mBitsPerSecond;
 
+  TimeStamp mStartTime;
+
   // DOMExceptions that are created early and possibly thrown in NotifyError.
   // Creating them early allows us to capture the JS stack for which cannot be
   // done at the time the error event is fired.
   RefPtr<DOMException> mSecurityDomException;
   RefPtr<DOMException> mUnknownDomException;
 
 private:
   // Register MediaRecorder into Document to listen the activity changes.

--- a/dom/media/encoder/TrackEncoder.cpp
+++ b/dom/media/encoder/TrackEncoder.cpp
@@ -224,16 +224,18 @@ AudioTrackEncoder::TryInit(const AudioSe
     // data yet. Motivated by issues like Bug 1336367
     TRACK_LOG(LogLevel::Warning,
               ("[AudioTrackEncoder]: Initialize failed "
                "for %ds. Attempting to init with %d "
                "(default) channels!",
                AUDIO_INIT_FAILED_DURATION,
                DEFAULT_CHANNELS));
     nsresult rv = Init(DEFAULT_CHANNELS, mTrackRate);
+    Telemetry::Accumulate(
+      Telemetry::MEDIA_RECORDER_TRACK_ENCODER_INIT_TIMEOUT_TYPE, 0);
     if (NS_FAILED(rv)) {
       TRACK_LOG(LogLevel::Error,
                 ("[AudioTrackEncoder %p]: Default-channel-init failed.", this));
       OnError();
       return;
     }
   }
 }
@@ -517,16 +519,18 @@ VideoTrackEncoder::Init(const VideoSegme
   }
 
   mNotInitDuration += aDuration;
   if ((mNotInitDuration / mTrackRate > VIDEO_INIT_FAILED_DURATION) &&
       mInitCounter > 1) {
     TRACK_LOG(LogLevel::Warning,
       ("[VideoTrackEncoder %p]: No successful init for %ds.",
        this, VIDEO_INIT_FAILED_DURATION));
+    Telemetry::Accumulate(
+      Telemetry::MEDIA_RECORDER_TRACK_ENCODER_INIT_TIMEOUT_TYPE, 1);
     OnError();
     return;
   }
 }
 
 void
 VideoTrackEncoder::Cancel()
 {

--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -9231,16 +9231,35 @@
   "WEBRTC_CALL_TYPE": {
     "record_in_processes": ["main", "content"],
     "alert_emails": ["webrtc-telemetry-alerts@mozilla.com"],
     "expires_in_version": "never",
     "kind": "enumerated",
     "n_values": 8,
     "description": "Type of call: (Bitmask) Audio = 1, Video = 2, DataChannels = 4"
   },
+  "MEDIA_RECORDER_RECORDING_DURATION": {
+    "record_in_processes": ["main", "content"],
+    "alert_emails": ["bvandyk@mozilla.com"],
+    "expires_in_version": "60",
+    "kind": "exponential",
+    "high": 3600,
+    "n_buckets": 100,
+    "bug_numbers": [1400757],
+    "description": "The length of time (in seconds) that a recording lasted. Recorded when a recorder stops"
+  },
+  "MEDIA_RECORDER_TRACK_ENCODER_INIT_TIMEOUT_TYPE": {
+    "record_in_processes": ["main", "content"],
+    "alert_emails": ["bvandyk@mozilla.com"],
+    "expires_in_version": "60",
+    "kind": "enumerated",
+    "n_values": 4,
+    "bug_numbers": [1400757],
+    "description": "Records the type of timeout that happened while attempting to init the encoder. Audio = 0, Video = 1. Recorded immediately following a timeout"
+  },
   "DEVTOOLS_ENTRY_POINT": {
     "record_in_processes": ["main"],
     "bug_numbers": [1378863],
     "alert_emails": ["dev-developer-tools@lists.mozilla.org", "apoirot@mozilla.com"],
     "expires_in_version": "60",
     "kind": "categorical",
     "labels": ["KeyShortcut", "SystemMenu", "HamburgerMenu", "ContextMenu", "CommandLine"],
     "releaseChannelCollection": "opt-out",

--- a/toolkit/components/telemetry/Scalars.yaml
+++ b/toolkit/components/telemetry/Scalars.yaml
@@ -628,16 +628,31 @@ webrtc.nicer:
     kind: uint
     notification_emails:
       - webrtc-ice-telemetry-alerts@mozilla.com
     release_channel_collection: opt-in
     record_in_processes:
       - 'main'
       - 'content'
 
+mediarecorder:
+  recording_count:
+    bug_numbers:
+      - 1400757
+    description: >
+      The number of times a MediaRecorder has been started. Recorded when a MediaRecorder starts
+    expires: "60"
+    kind: uint
+    notification_emails:
+      - bvandyk@mozilla.com
+    release_channel_collection: opt-in
+    record_in_processes:
+      - main
+      - content
+
 # The following section contains content process base counters.
 dom.contentprocess:
   troubled_due_to_memory:
     bug_numbers:
       - 1305091
     description: >
       The number of content processes that were marked as troubled because
       it was running low on virtual memory.