follow.it - follow.it gets publishers more followers & recurring traffic, and provides a better reading experience for followers
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.
Superfeedr - Real-time feed API - RSS and Atom over PubSubHubbub and XMPP. Superfeedr pushes RSS feeds in real-time for both publishers and subscribers, with open protocols and APIs.
FeedBlitz - FeedBlitz is a mega pack solution for social media marketing and RSS feed and subscriber integration.
Mixpanel - Mixpanel is the most advanced analytics platform in the world for mobile & web.