I think if your competitors are posting on your blog as long as its beneficial thats great, if it generates more discussion on your chosen theme then thats helpful to everyone.
I’m quick to delete comments from my blog from those who are just link spamming and seem to be getting craftier in their techniques – usually long winded replies that offer little in content value or opinion.
I do think blogs are great for B2C businesses to directly promote sales of their items so not too worried if I hit a ourely commercial blog – as long as the benefits on offer outweigh the fact that the site is using the blog to flog stuff. I have some clients who use their blogs to this effect particularly well and in some occasions have seen increases of traffic double to their own sites when the offers are well received.
