Recently, we've seen on the Joomla forums users asking around on how to enable video comments on their Joomla website. This is a great way to keep your customers engaged, if you are able to get your customers to engage with video comments, you're doing great at Social Media (if you aren't have a look at our 101 tips for Social Media). By the way, if you haven't already, make sure you've enabled some kind of commenting system on your Joomla website!
Disqus for Joomla. The great thing about Disqus is that it has become quite popular as a global commenting system across sites, so users won't have to register or login to be able to comment. Disqus also allows the extended functionality of video comments, so not only you would get support for Disqus comments but also great engagement using video comments!