Just gave it a (very) quick look

> a static site is a site with no fancy clicky things, signups, comments, just plain html

Technically I think you can have comments via some embedded widget. Each page is still static, but there's a script tag in there that embeds a widget into the page that gives you commenting, usually via some SaaS

I think Disqus was the big one for a while. There was one I saw recently that uses github as the auth provider, which was interesting