- Due to the above, it helps you understand the topic you're writing about better
- It can help find other like-minded individuals
- For business blogging, it can help you find potential collaborators/partners, and maybe just as important, the existence of competitors. As might already be obvious, it can help drive traffic to other things you might care about (your startup, favorite causes, whatever.)
- Based on the feedback you get, you can refine (or rethink) your arguments
- It can help establish you as someone knowledgeable about the topics at hand. Due to this, you may receive inquiries for your thoughts on some aspect of the subject, related ones, recent news about the subject, etc.
HTH