From their website:
The Easiest Blog, Ever
Postach.io is the easiest way to publish the thoughts you're already capturing in your Evernote. If you currently have notes in your Evernote account, you're ready to publish right now.
No CMS Required
Why learn a CMS when you already use Evernote? Simply select a notebook, add a domain name, then tag notes as "published" to share great content. It's that easy.
Your Data Belongs To You
You'll never need to migrate your posts to a haven. Since your Evernotes are stored locally on your machine or mobile, your data is always in your possession and easy to take with you.
Roll Your Own Theme
Inspired by the ease of Tumblr, rolling a Postach.io theme is as easy as creating a single HTML page with inline CSS. We include the technical stuff like Google Analytics, Disqus commenting and share buttons.