Hi Alexia, I'm a big fan of Zapier and Invision, both of which I think have more than successfully achieve this milestone. Although they have lots of posts written by their own employees, they do regularly invite independent industry related bloggers to contribute.
Zapier's Blog: https://zapier.com/blog/
Invision's Blog: http://blog.invisionapp.com/
Love to hear which other examples has this community found!