We have been using Google analytics for several years on ArticleAlley, the information available is really helpful and also free! The following shows the split of our daily visitors by browser type, whats interesting is the rapid uptake of Google Chrome their own free browser.

We have had some issues in the office with internet explorer and I know a lot of people use firefox, maybe Chrome will catch up quickly.

Google Analytic produces some very nice graphs which are always helpful when trying to interpret a mass of data.