Adweek:

"When people come to a page that has Disqus, we know what they’re reading," said David Fleck, gm of advertising at the company. "We know if they choose to comment. We know what they comment on and know what they say in that comment. We know if they voted on it, and shared it out to social networks." Disqus said its metadata are used to create anonymous profiles against which brands could target ads, without sharing personally identifiable information. "We have the largest and deepest audience profiles on the Web," Fleck said.

Another ad format for digital marketers.