> What websites your visitors consume is IMHO not your business.

But if your product is the subject of discussion on another page which links to yours, you may want to be able to join the discussion.

As a site owner, I don't think it's unreasonable to ask my visitors how and where they found out about my website.

It's two very different things if the sudden spike in page views is because of nytimes.com or reddit.com.