The other day -based upon some twitter messages I was doing with some friends- I thought about how many RSS readers I have for my frontpage. I didnt feel like investigating /all/ possible RSS readers since every taxonomy item in Drupal (the CMS under this site) is a RSS feed and since since only very few people are subscribed to these feeds; most follow the frontpage.
The problems with RSS readers is that big aggegator sites get the RSS feed on behalf of multiple people, just counting readers does not do the job. Fortunately, bigger sites mention how many people are reading the feed, like this in the headers:
(+http://www.google.com/feedfetcher.html; 12 subscribers;
The other problem is that I have three RSS feed URL's for one and the same feed:
/myblog/atom/feed
/myblog/node/feed
/myblog/rss.xml
So I run the following code on an access log of half a day:
[root@tug httpd]# grep "/rss.xml" access_log | awk '{print $1, $11, $12, $13, $14, $15, $16}' | sort | uniq -c | sort -rn | more
[root@tug httpd]# grep "/myblog/node/feed" access_log | awk '{print $1, $11, $12, $13, $14, $15, $16}' | sort | uniq -c | sort -rn | more
[root@tug httpd]# grep "/myblog/atom/feed" access_log | awk '{print $1, $11, $12, $13, $14, $15, $16}' | sort | uniq -c | sort -rn | more
(note: Most RSS readers grab the feed muliple times per day. I dont count them via the onliners above and having only half a day of sampling data is not that bad)
Then count the "on behalf of xxx subscribers" by hand and...
I couldn't believe it, in half a day I have some 554 subscribers! Wowsers!