Commento is abandoned. I strongly recommend using Comentario instead.
A while ago I’ve made a decision to migrate off Disqus, which is arguably the most popular external commenting system for website owners.
The problem with Disqus, as with many other “free” products, was that you’re most likely the product here. It has a ridiculously huge footprint (think megabytes) and “enriches” your page with more than a hundred additional HTTP requests.
Next to that, it shows ads—which you can buy off at “only” $9/month with their Plus plan. How bad should it be to start to search for alternatives?