If you ask the team, the reason I blog is because they hope that it keeps me quiet so they can help with your recruitment needs, they forget i can multitask ;)
Anyway, Why do people blog? For some its a like a window into someone's personal thoughts & hobbies - they might not feel confident enough to speak out - they might prefer pen to paper and this way they wont ever lose their thoughts or feelings.
For others its a great way to bring people together around an important topic - sometimes it can become a heated topic - Politics for example.. Blogging is a great way to bring together like-minded people. If you like to write, you can create a blog to showcase your skill.
When it comes to recruiting even employers are now wanting to hire people who know what they are doing or at least show potential by writing a blog that showcases expertise in a certain area, you can demonstrate to prospective employers that you have the required knowledge and career goals for a job within their company.
What's the most interesting blog you've read or written recently?