A blog allows you to expose a little about your personality, thoughts and beliefs. This can help you build trust with potential clients before you even speak to them. It can also help you explain core ideas that help sell your product or service. You can expand this by not only blogging, but also by writing articles in your area of expertise. People, especially investors, want to work with experts. A blog is a place to let your expertise shine and show people how you do business. It is a classic push marketing tactic.
It will take a not insignificant amount of your time to get going. Blogging, done correctly, requires a consistent effort. Will it be worth it? I guess that depends on what you have to say.