One of the fastest ways to gain authority in a specific target market or niche is to use blogging as a means to share content. Blogging allows you to focus on a topic, or a series of topics, and provide insight and expertise to that area. The goal is to create as much value as possible for your readers so that they continue to come back for more.
Anyone who is in the business of selling information products should also be in the business of blogging. You can't credibly take an authoritative stance via an information product if you don't let people sample the content and get a little taste of what is to come when they take their wallets out. People need a platform to get to know you better and make the decision for themselves - is this something that is going to help me with my current problem?
Your blog can either be an external entity, which is attached to your website by way of a link, or you can have it condensed together into one, seamless blog-based website. In our work with our clients, we highly recommend that they integrate their entire site and their blog onto the WordPress platform. This gives them the benefits of the blogging platform (easy to update, highly search engine optimized, plugin integration that adds more functionality to your site, etc.) and it makes the user experience seamless.
The blog is going to be your opportunity to take advantage of the one-to-many principle. I am sure that you find yourself answering many, many questions to your target audience in a one off format. You may even be answering the same questions over and over again. Instead of answering back to each personally individually, turn those questions into blog posts and send them a link to the post once it is published.
The blog should be your jumping off point for your information products. What I mean by that is you should be analyzing, on an on-going basis, which of your content is the most popular, which of your content gets the most discussion and which of your content is the most shared. The popular posts will point you in the direction of the types of information products you should create.