Post, Post, Post, Post, Post, Post, And Then Post Again
If you’ve already added a blog to your site, you should post, post, post, and then post some more. Each time you publish a blog entry, the blog search engines will index it - if your blog is set to ping.
Posting once a month won’t get you much exposure, but posting multiple times each day can get you a significant amount. People are watching blog search engines and using them all day long, and adding content daily can bring ample visitors. Technorati and Google Blog Search are probably the most popular search engines that index and update their results when posts are published.
Posting multiple times per day can also help you to develop a following that your blog couldn’t get otherwise. Getting people hooked on coming back multiple times each day can drive your Alexa ranking through the rook - actually lower is better with Alexa so let’s say it this way: Getting people hooked on coming back multiple times per day can make your Alexa sink like the Titanic… that doesn’t sound right either. 
Lesson learned: post a lot and then post some more.