You can connect your community with a web analytics application such as Google Analytics or WebTrends. When you have an account with a web analytics provider, then add their script via the admin console, the script is automatically inserted by the application at the bottom of its pages. The script isn't typically displayed to people, nor are the analytics results displayed in the admin console (you get them from your analytics provider).
Admin Console: Reporting > Settings > Third-Party Integration
To set up a connection with an analytics application, under Reporting Settings click Enabled, then paste your script code into the box provided.
Here's are two examples of what you might enter in the admin console:
<script src="www.google-analytics.com—urchin.js <http://www.google-analytics.com/urchin.js>"
type="text/javascript">
</script>
or
<script type="text/javascript">
_uacct = "AB-123456-1"; urchinTracker();
</script>