<i>It is more effective bandwidth wise because the data can be limited based on connection speed.</i><p>Forums since the early days of the Web could do this too - only showing the first <i>n</i> posts, and paging to let you view more. And they didn&#x27;t require JavaScript or any of the other fancy new features browsers have today.<p>Edit: How much bandwidth would be taken up by loading a few hundred plaintext comments, keeping in mind this is a YouTube page containing an embedded video which will be at least an order of magnitude bigger?<p><i>As well as having a back fall system for users with browsers that cannot support such functionality.</i><p>That&#x27;s what all_comments was.