Disqus was the default commenting system for a Ghost blog theme I purchased for my humble website. It actually broke my site's functionality by directing users who had made comments to really shady advertisements. You can see a screen recording of the behavior here: https://keeganleary.com/disqus-is-evil-trash/

I switched out for ComentBox and let the theme designer know about the issue. I will also forward him this article and have a look at some of the other comment systems provided! Thanks!