The subscriber stats show you all the users that have active email subscriptions to your blog using the built-in email notification system on WordPress.com. They don’t include users that subscribed using a third-party subscription service or using RSS.
Your site stats page http://en.support.wordpress.com/stats/ displays how many followers you have, who your followers are, as well as how many people are subscribed to post comments on your site.
On that page scroll down to “Totals, Followers & Shares”
Then click the links.
Site followers: __active followers
Comment followers: __ followers, __ following