Google Tag Manager lets you add and update your website tags, easily and for free, whenever you want, without bugging the IT folks. [Google] Google Tag Manager [GTM] Was Released on 1st October 2012 To help Webmasters , IT guys & marketing Gurus To help Manage their Google Analytics tags, Bing , Remarketing codes , Google adwords Campaigns Codes etc in One Place . Truth is that there are So many Tracking codes to Track your Website . Google Tag manager helps to manage All these Easily