Anybody who has a blog or a website loves to know how many people visit their site. In early days of the web these took the form of simple counters, but they don’t really tell you a lot of information about your visitors.
I’ve been using Google Analytics for about 5 years or so now, and it’s very easy to implement on your site or blog and once set up you just look at the reports and data that Google collects on your behalf from your visitors from a cookie. It is a free to use service, I have it set up on a lot of sites, so I can look at them all at the same time.