Counting RSS Readers
Last night, Martin Schwimmer was asking about counting RSS readers. Greg Reinacker has posted on counting subscribers before. Here's how a sample implementation might go:
- Establish a public RSS feed http:\//yourhost/public.xml. Use this url on your web pages and in your auto-discovery links.
- Publish the real RSS feed as http:\//yourhost/rss.xml.
- Implement the public feed as a redirection script. When the public feed is requested, the script responds that the feed has permanently moved to http:\//yourhost/rss.xml?id=unique_number. The news reader should silently replace the public feed with the uniqueified feed.
- The numbers of subscribers is the number of unique id value/client pairs in a given period minus robots plus subscriber counts (as provided by Bloglines).
This method is immune from network ip-address issues (multiple users sharing an address and mobile individuals with multiple addresses). It will under count subscribers when the uniqueified feed is shared via direct sharing/distribution of a subscription list and the sharers use a common RSS aggregator.
FeedBurner counts unique ip-address/client pairs, swapping a shared feed under count for a multiple ip-address over count. I think that under counting should be preferred over over counting until feed sharing becomes prevalent.
Personally, I just open up my access log and winnow the data down to rss.xml access in a given day (about 35 subscribers yesterday). But I like to look at the ip addresses and try to identify my subscribers.
18 June: If log analysis shows that an uniqueified url is being shared, then those readers could just be redirected to a new url out of the pool.