title: Why google Tag Manager uses IFrame and not the script DOM element?
body: <p>Any reason why Google Tag manager uses hidden IFrame solution? I am referring to this page <a href="https://developers.google.com/tag-manager/quickstart" rel="nofollow">https://developers.google.com/tag-manager/quickstart</a>. Why does it not use the script DOM element approach, like the one described here <a href="http://www.stevesouders.com/blog/2008/12/27/coupling-async-scripts/" rel="nofollow">http://www.stevesouders.com/blog/2008/12/27/coupling-async-scripts/</a>? Thanks. </p>