Some companies pay people to post spammy comments on blogs. They will pay desperate fools a penny or two to post comments that are supposed to look like legitimate advice, but that are really just intended to link back to a product website. These products are usually just scams. I've seen people trying it here. Currently, the most common one has to do with phony hair-restoration treatments. But it is a waste of time, since comments here are moderated. No one (except the moderator, who doesn't care) will see the spam. And the stupid person posting the spam won't get paid, because they get paid only for comments that are visible. The good news is, that the more time they spend trying to post spam on moderated blogs (and the more time their spam masters spend checking their work), the less time they have to post their garbage elsewhere.