Whether you take Google, Bing, Altavista or Ask, any and every search engine likes fresh content. They like websites and pages that are updated frequently and typically increase their ranking in the system. If a page is never updated, Google perceives that website to be a thing of the past, and lowers its ranking. Blogging is a way for websites with content not regularly updated to let search engines know that their website is still being maintained.

Another benefit of blogging is the inclusion of images. Having relevant images on a blog allows Google to not only find you through the traditional web search, but also through image search. In a sense, it's also an SEO tool. 

And finally, the last benefit: Intriguing your viewers with relevant information to your topic. Having fresh content keeps your viewers loyally coming back to see what's new, and keeps an outdated website, or an updated website, fresher than ever.

Having those juicy keywords helps too. Blogging is a free and easy marketing technique, that keeps those search engines and viewers coming back for more.