Google Reader Subscribers

I love Google Reader and have been using it for about 4 months to manage the 189 RSS feeds I currently care about. (Here are my shared items for anyone that is interested.)

While browsing the Google Reader FAQ looking for how to get vquences embedded properly I came across the following.


Does Google Reader report subscriber counts?

Yes, Google Reader reports subscriber counts when we crawl feeds (within the “User-Agent:” header in HTTP). Currently, these counts include users of both Reader and Google; over time they’ll also include subscriptions from other Google properties.

Here is an example from my logs

209.85.238.4 – – [26/Jul/2007:07:31:54 +1000] “GET /blog/feed/atom/ HTTP/1.1” 304 0 “-” “Feedfetcher-Google; (+http://www.google.com/feedfetcher.html; 5 subscribers; feed-id=15287401989222975041)”

This is something I’ve always wanted to know. The stats aren’t particularly interesting but does point out an optimisation Google could make.

  • /blog/feed/atom/ – 5 subscribers
  • /blog/feed – 2 subscribers
  • /blog/feed/ – 1 subscriber

ie the last 2 are identical (note the difference is the trailing slash) and they are all pointing at the same blog. It would be cool if Google worked out the above are all exactly the same and only probed once.

Even more interestingly Google is probing these URLs at different frequencies.

  • /blog/feed/atom/ – Every hour
  • /blog/feed – Every hour
  • /blog/feed/ – Every 3 hours

Looks like it might be related to the number of subscribers, would be interesting to see other peoples data here.