Here it is! The nightmare of managing all your Google scripts/tags is over.
Do you have to spread over thousands of pages your AdWords conversion tags, Analytics goal tags, campaign tracking scripts, etc.?
You know what I'm talking about: injecting code, conditional JavaScript, custom tags in many different pages is really error prone, but here comes the solution from Google: Google Tag Manager.
Using the free Google Tag Manager tool, you have just to put ONE tag into each page, the SAME tag for every page.
Next you can handle all your tags with the centralized Google tool, your pages will pick them up from Google servers; yes, no more updates to your pages.
Take a look at the introductory video.