Why does any social site like Reddit use this method?
<p>See what <a href="http://en.wikipedia.org/wiki/Reddit" rel="nofollow">Reddit</a> uses to add one of its buttons:</p>

<pre><code>&lt;script type="text/javascript" src="http://www.reddit.com/button.js?t=2"&gt;&lt;/script&gt;
</code></pre>

<p>This JavaScript adds an <code>&lt;iframe&gt;</code> to the page, then the <code>&lt;iframe&gt;</code> adds the HTML code.</p>

<p>Why doesn’t the JavaScript add the HTML directly?</p>
