Michael Nguyen, whose Social Patterns blog often has cool stuff, wrote an entry last week that made me wonder about som continuing myths in SEO:

Before optimization a site is converting about 3% of its traffic. After optimization, it’s converting about 2% of its traffic but I’ve increased the traffic to the site by 50%. Not bad right? I only lost about 1% conversion, but I’ve increased traffic by a whopping 50%.

I think Michael's using this as an example, and I seriously hope that he's never lost conversions after "optimizing", but this isn't a one-time issue. Many of the inquiries for new business that I field have a component of fear related to the optimization process possibly making a site less attractive to visitors, more spammy-looking (there must be a better adjective to describe that) and less conversion-prone in general.

My goal when working with any site is to improve not only traffic, but also conversion rates. The two are inextricably tied together. How is it that SEO can make a site less user-friendly when our primary work is making the site attractive to visitors, potential linkers and search engines? These groups all have the same desire - high quality content, descriptive title tags and text & a usable experience.

What am I missing? Are there really elements of SEO that make a site less conversion-friendly?