I just started working with a rather large site that has over a million indexed pages in Google. Currently, they have very little tracking in terms of SEO performance. They are not currently tracking conversions (they're not a typical e-commerce site) by any Marketing Source - much less SEO which is the main source of site traffic.
My question is how are you measuring SEO conversions/sales and a how deep a level? By just SEO or at the category or keyword level? Most companies I've worked at previously hard coded marketing source ID's into all external links and internal links. I doubt that's the best solution at this point in time.
Also, do you use Google Analytics or an in-house developed Marketing Source tracking solution.