Two tips I gave recently to a colleague just setting out with Disqus.
Q. How do I make Disqus comments visible to Google?
If you are using an ESI caching solution you might be tempted to implement an ESI include to fetch the comments as they are dynamic content. I’d recommend not doing this as you’ll be fetching the comments (from your cache, or Disqus) on every page load which is very unnecessary just for the occasional visit by Google.
Q. What should I use for the disqus_identifier?
A. I recommend using an internal identifier for the piece of content to which the comment is attached prefixed with an environment indicator, e.g. disqus_identifier = ‘live_ 21EC2020-3AEA-1069-A2DD-08002B30309D’. I’d strongly suggest that you do not leave it blank and do not use the page URL. If you leave it blank Disqus will automatically use the URL which may not be permanent, thus when the article title changes (which is regularly included in a URL), the comments will be lost. Prefixing the environment to the identifier mitigates any clash with comments made in your testing environment when you move your CMS data around.