This tool is super useful, we use it all the time. Let's say that you've changed your phone number and you want to find every page where the phone number appears. Just pop in your old phone number into the keyword search. Then, select all 'Page Types' and click 'Search'. Now you can see a list of all pages that contain your old phone number. Be sure to update your phone number in the global site settings area (found via the main menu icon, in the top left).