diff --git a/app/models/ad_image.rb b/app/models/ad_image.rb
index dfbef35..efc3c9f 100644
--- a/app/models/ad_image.rb
+++ b/app/models/ad_image.rb
@@ -15,7 +15,7 @@ class AdImage
   field :deadline , :type => DateTime
   field :youtube , :type => String
   field :language_enabled, :type => Array, :default => ["en","zh_tw"]
-  field :exchange_item
+  field :exchange_item, :default => "1"
   LINK_OPEN_TYPES = ["local", "new_window"]
 
   belongs_to :banner