There's a free WP plugin (@steempress) that shares your blog posts on the Steem blockchain on autopilot. Find it here.
On the Steempress page you can read:
The delay feature allow you to publish first on your blog and then publish to steem after a few days/hours/minutes (you decide the delay). Which means that google and other search engines will index your blog first and tag steemit.com as a duplicate. And so your blog’s seo ranking won’t be hurt.
We recommend a 7 days delay for maximum security.
However, I never use the option to delay my posts. I should, but I don't. The main reason I set up that blog is that I want to be in control of my content and not lose everything when the Steem blockchain would be wiped out (which is very unlikely, of course).
Also, SteemIt only just re-introduced an RSS feature. It used to be a hassle, going through FetchRSS, then Feedburner to be able to have a feed URL for your blog. A WP blog has an RSS feed automatically...
I often forget about the WP blog, though. Then I'm halfway done writing my post in markdown using the Steempeak editor, and too lazy to transfer it to the WP blog, lol.