This free service that Google is offering really impresses me. I see how it benifits Google, but it is a real service that many folk pay premium dollar for. And it appears that Google isn't holding anything back with quality either.
Google Analytics tells you everything you want to know about how your visitors found you and how they interact with your site. You'll be able to focus your marketing resources on campaigns and initiatives that deliver ROI, and improve your site to convert more visitors.
http://www.google.com/analytics/