Originally Posted by rtucker
Plus, typical business sites are static in nature since after all they're there to inform others about their site. That's where blogs come in, to redirect your audience's attention into something related to your business still but more engaging and most of the time demands user interaction.
I agree with @rtucker + my 2 cents:
We run a corporate blog on WP and it works very well in terms of traffic generation and sales generation too though we try to minimize our sales pitch to cater to users familiar with the product AND also to those who stop by to read posts related to our industry. we do not run any ads - the blog is purely for customer interaction and information sharing, and for traffic as I said earlier.
I think that in terms of SEO, it is obviously better to have a corporate blog right on your site but it is very very expensive to create a solution analogous to WP and pay someone regularly for managing things for you. So there is SEO benefit but I don't think it offsets IT/labor costs of developing a blog on-site.
Also, as others mention on here, a blog should be informative and frequently updated. If you don't have the time, money and human resources to keep an informative corporate blog, do guest blogging, promote your posts in social media etc etc, then it's probably better not to start one at all..