It piqued my interest when one local web designer recently posted an article about SEO success they had achieved for a client. They had managed to get their client's website to number 1 on Google for a particular keyphrase and, naturally, wanted to big themselves up. Nothing wrong with that, after all, credentials and past success are important in order to highlight your skills to potential clients.
Here's the problem - a quick look on Google's keyword tool, Wordtracker and Overture shows no data available for the number of monthly searches the keyphrase that the client is number 1 on Google for. This suggests that the keyword is very niche and is unlikely to be used by potential customers looking for the client's products. Now I don't know enough about the company's client to say that being number 1 on Google isn't a success, they may only need to sell a couple of products a year to make money and hence if one person a month finds them on the search engines and they can convert 20% they're doing alright.
My issue is that focusing simply on Google rankings is very misleading for clients, it would, after all, be fairly easy to become number 1 on Google for a keyphrase relating to most businesses that is so niche no-one competes for it, these keyphrases are normally easy to compete on because no-one searches for them. It is far better for SEOs/web designers to talk about SEO success in terms of actual increases in relevant, targeted traffic to the website, this in my opinion, should be the goal of SEO, not simply to have higher search engine rankings.
Then there's the whole other issue of whether a website actually converts traffic once it arrives - that's for another day though... What are your thoughts? If you do SEO how do you measure your own success? If you're a business looking for SEO how do you decide whether an SEO company or web designer is credible?