It lets people subscribe to your YouTube channel with a single click, without having to leave your site to log into YouTube or to confirm their subscription. The entire process happens in the widget.
Give it a try! All you need to do is embed the code below into the source code of your website or blog, in the same way you embed a YouTube video:
<iframe id="fr" src="http://www.youtube.com/subscribe_widget?p=[add YouTube Username here]" style="overflow: hidden; height: 105px; width: 300px; border: 0;" scrolling="no" frameBorder="0"></iframe>
All text source from YouTube official blog @ blogspot by Georges Haddad, Product Marketing Manager.
Compilation by Google Nilma Boston Rio