I think the key here is that grandpa talking about his dog will find in short order that his Posterous blog is full of Viagra ads. Just because the SEO spammer

I think the key here is that grandpa talking about his dog will find in short order that his Posterous blog is full of Viagra ads. Just because the SEO spammers haven't started using Posterous yet doesn't mean they won't pile on in droves once they realize it's possible.