Do you know what the key to a successful blog is? A loyal community of readers.  No, not those one-off readers who visit your website, read a blog post and disappear. I mean, sure it’s great to attract as many readers as possible, but it’s a waste of an opportunity if you don’t know whether they’ll return — and you’re not enticing them to comeback. This is exactly why building an email list is so crucial to any online business,…