Google revealing a feed's subscriber numbers isn't new, but I this morning I noticed two changes to Google Reader.
Subscriber Numbers
Clicking the show details link in Google Reader will reveal the number of subscribers and average posts per week of a given feed. No more pretending to add a feed and searching, you're one click away from some dirt on the feeds you read. How accurate is it though? I'm not sure over what time period the posts per week is calculated, or where the subscribers number comes from. For this blog I'm told I've got a whopping 6 subscribers, whereas FeedBurner shows I have an average of ~50, 14 of those being Google FeedFetcher. When I write, people listen.
Feedfetcher is how Google grabs RSS or Atom feeds when users subscribe to them in Google Reader or iGoogle. Subscriber counts include Google Reader and the iGoogle. Feedfetcher collects and periodically refreshes these user-initiated feeds, but does not index them in Blog Search or Google's other search services.
If FeedBurner is showing me the total number of iGoogle and Google Reader subs, what value is Google Reader showing me? More importantly, is referring to iGoogle as the iGoogle an innocent slip?
Received/Published Date
In the first image, you can see the reported subscriber count for GottaBeMobile (the site which feeds my TabletPC hunger) and that something published at 12:53 AM was picked up by Google Feedfetcher a minute later. This is definitely not the norm, with most feeds being checked about once an hour according to the Google Reader FAQ. The same FAQ says that feeds with fewer subscribers may be updated less frequently. But what about larger feeds, are they checked more frequently?
With 658k subscribers, Google Reader is picking up many of Engadget's posts before they're even written. With that as a baseline, my 6th grade book report on Sharks should be showing up here fairly soon.
It's not you, it's me
How do the numbers compare for you? Do you see a better correlation between what Google Reader and FeedBurner report? If you're not using FeedBurner, what does Google's FeedFetcher say your subscriber numbers are? Mashable has cried foul on a higher-level, but what about folks who aren't included as a default feed?
March 19th, 2008 at 1:15 pm
interesting. Feedburner says 889 readers from the Google Feedfetcher for my feed, while Reader says 848. i wonder if the disparity has to do with transparent redirects from older feeds.
March 19th, 2008 at 1:41 pm
The redirects might be giving you multiple feed-ids, and Reader is (somehow) not combining them.
It'd be nice if there was a more granular breakdown on Feedfetcher's end. How many are using iGoogle vs Reader. Maybe I should kill the CNAME for feeds.coreygilmore.com and instead configure a ProxyPass in Apache and bounce everything to Feedburner so I can see the raw logs.
More importantly since subscriber counts are reported through the User-Agent header, what would happen if I hit my feed with a dummy header like:
October 28th, 2008 at 10:46 am
Google Reader Stats Update…
Google Reader just released an update to the feed details pane, including a graph showing when posts are made, and when you read posts. A nice bit of extra information from the Trends page. I still question the accuracy of the subscription numbers,…