I use Medium, Wordpress.com, Blogger, LinkedIn, eFactor, Quora, Vator.tv, Social Media Today, Live Journal and publish & syndicate 40 blogs now for over 10 years. They each have their plusses and minuses and none is perfect. If you're looking to improve your Google rank then by all means use Blogger (Google owns it) as my Blogger blogs always rank higher than any other platforms on the Google search engine (funny how that works huh?).
For your company blog I would strongly suggest keeping it right where it is on your company website. If you're looking to increase subscribers and traffic to your company blog then backlink snippets of your posts to Twitter, Facebook, LinkedIn etc...
One thing you should NOT do is double post the same content on two different platforms as Google will penalize duplicate content. I also would not suggest paying for SEO services. Make the content relevant and post often and traffic will grow organically.
You must consider what it is you are attempting to do with your blog. Having a bunch of traffic and subscribers alone doesn't accomplish much if that traffic doesn't convert into sales now does it?