Nimbus allows you to track traffic to and from your Nimbus site using Google Analytics.
Navigate to your "Settings" page and click on Google Analytics.
Enter your Google Analytics Web Property ID into the field titled "Property ID". Be sure to leave off the "UA-" portion of the ID and only paste the numbers. Click "Save" and start tracking your analytics on Google.
If you need help creating and finding your Property Id visit Google Analytics Support for help.