Google have absorbed another web industry; that of sophisticated web analysis software. As detailed in their press release they acquired Urchin and opened up their analysis software for free under the name of “Google Analytics”.
While it has been integrated into their AdWords service, you can also track your other keywords too:
Do you buy keywords on search engines other than Google? If you do, Google Analytics tracks them – all of your keywords, on every search engine. For both paid search and unpaid search.