A blog is the perfect venue to showcase your expertise. Sure, a resume and a portfolio of past works are also important, but a blog can give you an edge over the competition.
Clients will be impressed if they see that you are able to produce quality work. But they will be even more impressed if they see that you actually teach other people how to do so, too.
Lets take a look at the Search Engine Optimization market, for instance. There are literally thousands of SEO consultants on the Internet. The vast majority have a website outlining the offered services. A few of them, however, have blogs where they share SEO principles, tactics and techniques.The blogs that contain the most accurate and useful information end up becoming “authorities” of the niche.