Hi there!
As the question mentions, I’m wondering how do Communities and Blogs usually work together! 
From my experience, the blog, accessible through the company’s website is accessible to all users, but is mainly created for prospects. It’s main aspect is inspirational and has a clear objective with call-to-actions for prospects (filling in a form, asking for a demo, downloading a report..).
A community as I envision it, on the other hand is a content portal, only accessible to customer users with P2P content, answers to questions, use-cases, events, support, etc.
I’ve only experienced managing closed communities (only available for customers) and I’m wondering what are the best practices for opening communities to the public or at least having a part of the community opened to non-customers.
What are the goals of an open community vs. the goals of a website blog?
What are the positive/negative aspects of having both?
Would love to hear from all of your experiences,
Thanks! 
