Blogs do three main things:
- Add fresh new content to your website, which the search engines love
- Create content that can be used elsewhere
- Establish you as an expert in your field
People will see your blog if they:
- Search by topic and it shows in the search results (hard to do)
- Follow a link you share elsewhere
- Are on your website already and go to the blog
You could write your blog first, create an email piece on the same topic, then reference your blog and share the link. Driving people to your website is good.
Sharing the same info on your social sites is also ok. Redundancy risk is low since most people do not connect with you on all 3; email, blog, and social media. But if they see it more than once, that is completely fine.
Use email to drive people to your social media and vice-versa. But have the goal of getting them to end up on your website at some point. While they are there, they may look around.