Feedburner, which I heard of from Fred Wilson, creates a feed which provides information on readers back to the publisher. Seems to me, publishers can give the reader a choice, and provide more service if the reader chooses to declare the relationship.
From the site:
What is it?
FeedBurner enhances your current RSS or Atom feeds in a variety of ways that YOU control, while simultaneously providing personalized usage and trend statistics that describe how your feed is being used.
How does it work?
1. Enter your syndication URL in the field at the top of the page.
2. On the subsequent page, select which services you would like FeedBurner to perform for you and your feed.
3. Use the new HTML that FeedBurner gives you for your syndicated feed, and we’ll do the rest. Your FeedBurner home page will begin to track and report your feed usage statistics for you.
To learn more about how FeedBurner works, check out the FAQ.