You should have a company blog. For the success of any site you need to have sufficient unique content to generate content that Google can use to associate with your company. I suppose for some businesses, you do not really need a strong online presence, but post-Panda I cannot really thing of any situation where one would not benefit greatly from having a blog. Just make sure to spin it into something interesting that would actually make someone want to read it. On one site I worked on for medicare supplement insurance the content to me was boring, but I had to remind myself that for people interested in this information, it was not.