Google Adds Subscriber Count to Webmaster Tools
According to King Ramon and Problogger, Google’s webmaster tools have added the ability to track how many subscribers your site has through the Google readers (Google, Google Reader and Orkut). From King Nomar:
If you want to check how many of your RSS Readers are Google subscribers go to subscriber stats, select the site from which you want to check the number, click statistics and than click on Google subscribers. There you have it, the number of RSS readers that are subscribed through Google on your site.
Yep, I tried it and yep, it works!