“The key is to keep your readers connected to, and consuming, current content, whether you’re pushing it to them via email, or they’re pulling it in via RSS, Facebook, Twitter or other social media subscription.”
There are many methods that you can use to get your message out beyond email, so consider email to promote these. Your email messages can include links for people to subscribe to your RSS feed, and they should include opportunities to receive your weekly email digest or special updates.
