Several WordPress.com bloggers are reporting significant drop in their feed subscriber counts by as much as 75%. This is being attributed to some tweaks done by the WordPress.com guys to remove duplicate counts caused by multiple queries from similar sources.
The WordPress forums has a sticky post explaining why initial feed statistics were artificially high
“When a service like Netvibes gets very large they start needing lots of machines to do the work, so these requests may start arriving from different machines. There may be as many as ten machines each reporting “30 subscribers” which makes it seem as though there were 300 subscribers. This was making your feed stats report a falsely high number of subscribers.”
And they say this will help in more accurate feed statistics now.
“A few minutes ago I updated the code to try to weed out the duplicates while respecting enterprise aggregators. Your feed stats may drop as a result. They may even crash. Unfortunately we cannot apply this change retroactively. On the bright side, this change means your feed stats will be more stable and accurate from now on.”
If you are redirecting your WordPress.com blog feed through Feedburner to track the number of your feed readers, have you noticed a drop in your feed subscriber count?