Freelance Copywriter's Blog has a nice post about the effects of SEO on copy.
We should of course be past the craziness of keyword stuffing by now. Sadly it still persists and still results in copy that's appears designed to repell readers and kill sales.
The post links to a video by Ian Lurie of Conversation Marketing and is 12 minutes well spent. Take a look:
How SEO ruins copy: And how your customers can help you fix it from ian lurie on Vimeo.