Quartz introduced their version of reader comments yesterday, calling them annotations. Similar to Notes on medium.com, readers can now comment on every paragraph in an article.
“The idea is to encourage thoughtful commentary and substantive contributions. Because you are annotating a specific paragraph, the discussion ought to be much more directed than usual. We’ll also reward your great annotations by featuring them more prominently, responding to you, and removing others that are off-topic or abusive.”