follow.it - follow.it gets publishers more followers & recurring traffic, and provides a better reading experience for followers
Feedbutler - Subscribe to your RSS feeds directly via email!
Feedio - Feedio helps bloggers manage and grow their email and RSS subscribers.
FeedPress - Custom hostname. You can customize FeedPress to use your own domain name to retain your website's brand. All you need to do to get started is simply register your domain name via your hostname management page.
FeedBlitz - FeedBlitz is a mega pack solution for social media marketing and RSS feed and subscriber integration.
Blogtrottr - Track RSS feeds and send updates to your email inbox.