diff --git a/app/models/site_setting.rb b/app/models/site_setting.rb
index 849890ad7..e257ee2f2 100644
--- a/app/models/site_setting.rb
+++ b/app/models/site_setting.rb
@@ -263,6 +263,8 @@ class SiteSetting < ActiveRecord::Base
 
   client_setting(:enable_mobile_theme, true)
 
+  setting(:dominating_topic_minimum_percent, 20)
+
   def self.generate_api_key!
     self.api_key = SecureRandom.hex(32)
   end
diff --git a/app/models/user_history.rb b/app/models/user_history.rb
index 81b41b0b2..5cb133bb4 100644
--- a/app/models/user_history.rb
+++ b/app/models/user_history.rb
@@ -17,7 +17,8 @@ class UserHistory < ActiveRecord::Base
                            :delete_site_customization,
                            :checked_for_custom_avatar,
                            :notified_about_avatar,
-                           :notified_about_sequential_replies)
+                           :notified_about_sequential_replies,
+                           :notitied_about_dominating_topic)
   end
 
   # Staff actions is a subset of all actions, used to audit actions taken by staff users.
@@ -47,8 +48,11 @@ class UserHistory < ActiveRecord::Base
     query
   end
 
-  def self.exists_for_user?(user, action_type)
-    self.where(target_user_id: user.id, action: UserHistory.actions[action_type]).exists?
+  def self.exists_for_user?(user, action_type, opts=nil)
+    opts = opts || {}
+    result = self.where(target_user_id: user.id, action: UserHistory.actions[action_type])
+    result = result.where(topic_id: opts[:topic_id]) if opts[:topic_id]
+    result.exists?
   end
 
   def new_value_is_json?
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 22f8a53cb..40bb36300 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -120,6 +120,12 @@ en:
 
       It's easier for everyone to read topics that have fewer in-depth replies versus lots of small, individual replies.
 
+    dominating_topic: |
+      ### Let others join the conversation
+
+      This topic is clearly important to you &ndash; you've posted more than %{percent}% of the replies here.
+
+      Are you sure you're providing adequate time for other people to share their points of view, too?
 
   activerecord:
     attributes:
@@ -698,6 +704,8 @@ en:
 
     enable_mobile_theme: "Mobile devices use a mobile-friendly theme, with the ability to switch to the full site. Disable this if you want to use a custom stylesheet that is fully responsive."
 
+    dominating_topic_minimum_percent: "What percentage of posts a user has to make in a topic before we consider it dominating."
+
   notification_types:
     mentioned: "%{display_username} mentioned you in %{link}"
     liked: "%{display_username} liked your post in %{link}"
diff --git a/db/migrate/20130917174738_add_topic_id_to_user_histories.rb b/db/migrate/20130917174738_add_topic_id_to_user_histories.rb
new file mode 100644
index 000000000..2b0c17946
--- /dev/null
+++ b/db/migrate/20130917174738_add_topic_id_to_user_histories.rb
@@ -0,0 +1,5 @@
+class AddTopicIdToUserHistories < ActiveRecord::Migration
+  def change
+    add_column :user_histories, :topic_id, :integer
+  end
+end
diff --git a/lib/composer_messages_finder.rb b/lib/composer_messages_finder.rb
index cc40873e3..d475cc62f 100644
--- a/lib/composer_messages_finder.rb
+++ b/lib/composer_messages_finder.rb
@@ -8,7 +8,8 @@ class ComposerMessagesFinder
   def find
     check_education_message ||
     check_avatar_notification ||
-    check_sequential_replies
+    check_sequential_replies ||
+    check_dominating_topic
   end
 
   # Determines whether to show the user education text
@@ -60,7 +61,7 @@ class ComposerMessagesFinder
                   (@user.post_count >= SiteSetting.educate_until_posts) &&
 
                   # And who haven't been notified about sequential replies already
-                  (!UserHistory.exists_for_user?(@user, :notified_about_sequential_replies))
+                  !UserHistory.exists_for_user?(@user, :notified_about_sequential_replies, topic_id: @details[:topic_id])
 
     # Count the topics made by this user in the last day
     recent_posts_user_ids = Post.where(topic_id: @details[:topic_id])
@@ -74,13 +75,44 @@ class ComposerMessagesFinder
               recent_posts_user_ids.detect {|u| u != @user.id }
 
     # If we got this far, log that we've nagged them about the sequential replies
-    UserHistory.create!(action: UserHistory.actions[:notified_about_sequential_replies], target_user_id: @user.id )
+    UserHistory.create!(action: UserHistory.actions[:notified_about_sequential_replies],
+                        target_user_id: @user.id,
+                        topic_id: @details[:topic_id] )
 
     {templateName: 'composer/education',
      wait_for_typing: true,
      body: PrettyText.cook(I18n.t('education.sequential_replies')) }
   end
 
+  def check_dominating_topic
+
+    # We only care about replies to topics for a user who has posted enough
+    return unless replying? &&
+                  @details[:topic_id] &&
+                  (@user.post_count >= SiteSetting.educate_until_posts) &&
+                  !UserHistory.exists_for_user?(@user, :notitied_about_dominating_topic, topic_id: @details[:topic_id])
+
+    topic = Topic.where(id: @details[:topic_id]).first
+    return if topic.blank? ||
+              topic.user_id == @user.id ||
+              topic.posts_count < SiteSetting.best_of_posts_required
+
+    posts_by_user = @user.posts.where(topic_id: topic.id).count
+
+    ratio = (posts_by_user.to_f / topic.posts_count.to_f)
+    return if ratio < (SiteSetting.dominating_topic_minimum_percent.to_f / 100.0)
+
+    # Log the topic notification
+    UserHistory.create!(action: UserHistory.actions[:notitied_about_dominating_topic],
+                        target_user_id: @user.id,
+                        topic_id: @details[:topic_id])
+
+
+    {templateName: 'composer/education',
+     wait_for_typing: true,
+     body: PrettyText.cook(I18n.t('education.dominating_topic', percent: (ratio * 100).round)) }
+  end
+
   private
 
     def creating_topic?
diff --git a/spec/components/composer_messages_finder_spec.rb b/spec/components/composer_messages_finder_spec.rb
index cf6f62478..1451aeaa1 100644
--- a/spec/components/composer_messages_finder_spec.rb
+++ b/spec/components/composer_messages_finder_spec.rb
@@ -12,6 +12,7 @@ describe ComposerMessagesFinder do
       finder.expects(:check_education_message).once
       finder.expects(:check_avatar_notification).once
       finder.expects(:check_sequential_replies).once
+      finder.expects(:check_dominating_topic).once
       finder.find
     end
 
@@ -136,10 +137,16 @@ describe ComposerMessagesFinder do
       end
 
       it "doesn't notify a user it has already notified about sequential replies" do
-        UserHistory.create!(action: UserHistory.actions[:notified_about_sequential_replies], target_user_id: user.id )
+        UserHistory.create!(action: UserHistory.actions[:notified_about_sequential_replies], target_user_id: user.id, topic_id: topic.id )
         finder.check_sequential_replies.should be_blank
       end
 
+
+      it "will notify you if it hasn't in the current topic" do
+        UserHistory.create!(action: UserHistory.actions[:notified_about_sequential_replies], target_user_id: user.id, topic_id: topic.id+1 )
+        finder.check_sequential_replies.should be_present
+      end
+
       it "doesn't notify a user who has less than the `sequential_replies_threshold` threshold posts" do
         SiteSetting.stubs(:sequential_replies_threshold).returns(5)
         finder.check_sequential_replies.should be_blank
@@ -166,5 +173,85 @@ describe ComposerMessagesFinder do
 
   end
 
+  context '.check_dominating_topic' do
+    let(:user) { Fabricate(:user) }
+    let(:topic) { Fabricate(:topic) }
+
+    before do
+      SiteSetting.stubs(:educate_until_posts).returns(10)
+      user.stubs(:post_count).returns(11)
+
+      SiteSetting.stubs(:best_of_posts_required).returns(1)
+
+      Fabricate(:post, topic: topic, user: user)
+      Fabricate(:post, topic: topic, user: user)
+      Fabricate(:post, topic: topic, user: Fabricate(:user))
+
+      SiteSetting.stubs(:sequential_replies_threshold).returns(2)
+    end
+
+    it "does not give a message for new topics" do
+      finder = ComposerMessagesFinder.new(user, composerAction: 'createTopic')
+      finder.check_dominating_topic.should be_blank
+    end
+
+    it "does not give a message without a topic id" do
+      ComposerMessagesFinder.new(user, composerAction: 'reply').check_dominating_topic.should be_blank
+    end
+
+    context "reply" do
+      let(:finder) { ComposerMessagesFinder.new(user, composerAction: 'reply', topic_id: topic.id) }
+
+      it "does not give a message to users who are still in the 'education' phase" do
+        user.stubs(:post_count).returns(9)
+        finder.check_dominating_topic.should be_blank
+      end
+
+      it "does not notify if the `best_of_posts_required` has not been reached" do
+        SiteSetting.stubs(:best_of_posts_required).returns(100)
+        finder.check_dominating_topic.should be_blank
+      end
+
+      it "doesn't notify a user it has already notified in this topic" do
+        UserHistory.create!(action: UserHistory.actions[:notitied_about_dominating_topic], topic_id: topic.id, target_user_id: user.id )
+        finder.check_dominating_topic.should be_blank
+      end
+
+      it "notifies a user if the topic is different" do
+        UserHistory.create!(action: UserHistory.actions[:notitied_about_dominating_topic], topic_id: topic.id+1, target_user_id: user.id )
+        finder.check_dominating_topic.should be_present
+      end
+
+      it "doesn't notify a user if the topic has less than `best_of_posts_required` posts" do
+        SiteSetting.stubs(:best_of_posts_required).returns(5)
+        finder.check_dominating_topic.should be_blank
+      end
+
+      it "doesn't notify a user if they've posted less than the percentage" do
+        SiteSetting.stubs(:dominating_topic_minimum_percent).returns(100)
+        finder.check_dominating_topic.should be_blank
+      end
+
+      it "doesn't notify you if it's your own topic" do
+        topic.update_column(:user_id, user.id)
+        finder.check_dominating_topic.should be_blank
+      end
+
+      context "success" do
+        let!(:message) { finder.check_dominating_topic }
+
+        it "returns a message" do
+          message.should be_present
+        end
+
+        it "creates a notitied_about_dominating_topic log" do
+          UserHistory.exists_for_user?(user, :notitied_about_dominating_topic).should be_true
+        end
+
+      end
+    end
+
+  end
+
 end