I believe privacy is important. Understanding how your private information is accessed and used is important to protecting it.
It is now normal that private information about your usage patterns of websites is collected and analysed by large advertising businesses. A good explanation on how and why they do this from a business perspective can be found here.
On balance, I prefer not to use this service anymore.
Google Analytics collects anonymised data about visits to websites.
Google Analytics works by accessing Cookies and other data that is transmitted by your web browser while you travel around the web. Google Analytics records from your visits various things including: what website you came from, how long you stay for, what kind of computer you’re using, your IP address, etc.
Google collects and stores this data on their servers located in various locations around the world. Google will analyse this data and prepare reports. Google will also share this data with third parties if required to do so by law or if Google employs those third parties to process Google Analytics data for them. Google says they will never combine your IP address with other data that could identify you personally.
You can stop the installation of the Cookie on your computer by setting a preference in your web browser. Google also offers a browser plugin that you can install to permanently opt out of Google Analytics tracking.