Google has made it easier for web site operators to use its free web site Analytics tool, which is designed to give web site owners, advertisers and publishers more information about the traffic on their sites.

The service was previously restricted to invited users but demand exceeded expectations, Google said in a statement. Now the service is open to anyone once they have created an account.

Google said that Analytics offers enterprise-level functionality and could be integrated with its AdWords system to let web site operators see how well they are spending their advertising money. Because the system can see how users come to visit particular sites, and how they navigate them, Analytics can also be used to target spending in certain areas and increase return on investment.

In a blog post, Brett Crosby, senior manager for Google Analytics, said, “Regardless of how you use Google Analytics, what's important to me is that you're using it at all. In other words, the more you take action based on web analytics data, the better the internet becomes.”

Google has also published a guide to the service to help users set up the system correctly and to their exact preferences.