This is 100% on the mark, you should definitely own your own content. Syndicating it out to Medium is a great idea, particularly when you can get a rel=”canonical” tag for the original on Medium. Incidentally Medium has their own WordPress plugin that will allow you to quickly and easily syndicate your site’s content directly to Medium without needing to separately import it. It’s also available on a per post basis.
But, even with this, you’re only getting 50% of the value of having your own website because you’ve only got one way communication out. Next you’ll need communication back in. What if I said you could get a lot of the comments, likes, and interactions from those other silos back into your website too? This way the conversations others are having relating to your content also come back to your site and enrich it there? What if you could own all (or almost all) of the conversation around your content?
Think about it, what if there was an @mention functionality that worked from website to website instead of being stuck inside Twitter, Facebook, Google+, Instagram, Flickr etc.? Interestingly, it exists! And you can set it up for free with last year’s new W3C Webmention protocol which already has WordPress plugins ready to go. Roughly for WordPress you’ll need the Webmentions plugin, the Semantic Linkbacks plugin, the Syndication Links plugin, a few strategically placed rel=”me” tags on your site, (maybe some tweaks to your microformats on your theme), and a free Brid.gy account. Details for setting it up can be found on the WordPress pages of the indieweb.org website. I suspect if you’re strong enough to have figured out the tech for your article, you could probably have it up and running in under an hour or so. Then instead of feeding content from your blog to the black hole of social media, you could have actual two-way communication with many social silos! Now you won’t need to pay as much attention to those other sites as you can use your WordPress site as an “app” to interact with them instead.
I’m happy to help walk you through it if you’re interested and need help. My own personal site has some documentation of some of the above as well as examples of how it works.
In some sense, hopefully this post on my site will be an interesting exemplar. I own it and “loaned” or syndicated copies to Disqus and Twitter. Comments, likes and reposts you make to the Twitter copy will automatically be ported back here after the fact using Brid.gy. (Sadly, Disqus isn’t supported–yet.)