diff --git a/admin/app/models/cohort.rb b/admin/app/models/cohort.rb
index 86966cdea..d1213fe53 100644
--- a/admin/app/models/cohort.rb
+++ b/admin/app/models/cohort.rb
@@ -1,4 +1,131 @@
+require 'date'
+
 class Cohort < ActiveRecord::Base
 
+  KEY_SET_TOTAL = [:registered_users, :first_downloaded_client_at, :first_certified_gear_at, :music_sessions_user_history, 'play_jamtr', :jam_track_rights, :recorded_tracks, :friendships, :invited_users]
+
+  TOTAL_LABELS = {
+    registered_users:                'Registered Users',
+    first_downloaded_client_at:      'Downloaded app', 
+    first_certified_gear_at:         'Certified Gear',
+    music_sessions_user_history:    'Played Online', 
+    play_jamtr:                      'Played JamTrack', 
+    jam_track_rights:                'Purchased JamTrack',
+    recorded_tracks:                 'Made Recording', 
+    friendships:                     'Connected w/Friend',
+    invited_users:                   'Invite Others',
+  }
+
+  # KEY_SET_TOTAL = [:registered_users, :first_downloaded_client_at, :first_certified_gear_at, :music_session_histories, 'play_jamtr', :jam_track_rights, :recordings, :friendships, :invited_users]
+  KEY_SET_MONTH = ['reg_users', :first_downloaded_client_at, :first_certified_gear_at, 'visit0-1', 'visit2-5', 'visit6+', 'play_online0-1', 'play_online2-5', 'play_online6+', 'play_jamtr0-1', 'play_jamtr2-5', 'play_jamtr6+', 'redeem_jamtr', 'purch_jamtr', 'recordings', 'friendships', 'invited_users']
+
+  serialize :data_set, JSON
+
+  before_create do
+    self.data_set ||= {}
+  end
+
+  def self.date_tuples(from,to)
+    prec   = from.size
+    start  = Date.new(*from)
+    finish = Date.new(*to)
+
+    filter_on = [:day,:mon].first(3-prec)
+    filter = ->(d) { filter_on.all? {|attr| d.send(attr) == 1 } }
+
+    (start..finish)
+      .select(&filter)
+      .map { |d| [d.year,d.mon,d.day].first(prec) }
+  end
+
+  def self.cohort_date_ranges
+    starting = User.where(admin: false).order(:created_at).first.created_at
+    ending = Time.now
+    dates = self.date_tuples([starting.year, starting.month], 
+                             [ending.year, ending.month])
+    ranges = []
+    dates.each_with_index do |d1, idx|
+      d2 = dates[idx+1] || [Time.now.next_month.year,Time.now.next_month.month]
+      rr = Time.parse("#{d1[0]}-#{d1[1]}-1")..(Time.parse("#{d2[0]}-#{d2[1]}-1") - 1.second)
+      ranges << rr
+    end
+    ranges
+  end
+
+  def self.cumulative_cohorts
+    self.cohort_date_ranges.collect do |range|
+      unless cc = Cohort.where(start_date: range.first).where(cumulative: true).limit(1).first
+        cc = Cohort.new
+        cc.start_date = range.first
+        cc.end_date = range.last
+        cc.cumulative = true
+        cc.save!
+      end
+      cc
+    end
+  end
+
+  def _join_user(assoc_ref)
+    assoc_ref.active_record
+      .joins("INNER JOIN users AS uu ON uu.id = #{assoc_ref.foreign_key}")
+      .where(created_at: self.start_date..self.end_date)
+      .where(['uu.created_at >= ? AND uu.created_at <= ?', 
+              self.start_date, self.end_date])
+  end
+  
+  def _put_data_set(key, count, num_user)
+    self.data_set[key] = count
+    self.data_set["#{key}%"] = 100.0 * (count.to_f / num_user.to_f)
+  end
+
+  def self.user_attribute_within(attrib, cohort)
+    User.where(attrib => cohort.start_date..cohort.end_date)
+  end
+
+  def all_time!
+    num_user = self.class.user_attribute_within(:created_at, self).count
+    return unless 0 < num_user
+
+    self.data_set['registered_users'] = num_user
+    num_user = num_user.to_f
+
+    count = self.class.user_attribute_within(:first_downloaded_client_at, self).count
+    _put_data_set('first_downloaded_client_at', count, num_user)
+
+    count = self.class.user_attribute_within(:first_certified_gear_at, self).count
+    _put_data_set('first_certified_gear_at', count, num_user)
+
+    count = _join_user(InvitedUser.reflections[:sender]).count
+    _put_data_set('invited_users', count, num_user)
+
+    count = _join_user(RecordedTrack.reflections[:user]).count
+    _put_data_set('recorded_tracks', count, num_user)
+
+    count = _join_user(Friendship.reflections[:user])
+      .joins("INNER JOIN friendships AS fff ON fff.friend_id = uu.id")
+      .where(['fff.created_at >= ? AND fff.created_at <= ?', 
+              self.start_date, self.end_date]).count
+    count /= 2
+    _put_data_set('friendships', count, num_user)
+
+    count = _join_user(JamTrackRight.reflections[:user]).count
+    _put_data_set('jam_track_rights', count, num_user)
+
+    count = _join_user(MusicSessionUserHistory.reflections[:user]).count
+    _put_data_set('music_sessions_user_history', count, num_user)
+
+    self.save!
+  end
+
+  def monthly!
+    count = JamTrackRight
+      .where(redeemed: true)
+      .where(updated_at: self.start_date..self.end_date)
+      .count
+    self.data_set['redeemed_jamtracks'] = count
+    self.data_set["redeemed_jamtracks%"] = 100.0 * (count.to_f / num_user.to_f)
+
+  end
+
 end
 
diff --git a/db/manifest b/db/manifest
index 9cc4e1fac..bd94ccb90 100755
--- a/db/manifest
+++ b/db/manifest
@@ -260,4 +260,5 @@ jam_track_jmep_data.sql
 add_jam_track_bitrates.sql
 jam_track_importer.sql
 jam_track_pro_licensing_update.sql
-jam_track_redeemed.sql
\ No newline at end of file
+jam_track_redeemed.sql
+cohorts.sql
diff --git a/db/up/cohorts.sql b/db/up/cohorts.sql
index a9598189d..2fae882ca 100644
--- a/db/up/cohorts.sql
+++ b/db/up/cohorts.sql
@@ -1,9 +1,13 @@
-CREATE TABLE cohorts {
+CREATE TABLE cohorts (
     id VARCHAR(64) PRIMARY KEY DEFAULT uuid_generate_v4(),
 
     start_date TIMESTAMP NOT NULL,
     end_date TIMESTAMP NOT NULL,
-    group_type VARCHAR(64) NOT NULL,
+    cumulative BOOLEAN NOT NULL DEFAULT FALSE,
+    data_set JSON NOT NULL DEFAULT '{}',
     
     created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
-};
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX index_started_date ON cohorts USING btree (start_date);