Sites
Before using Periscope the user must choose which sites in the database are available to Periscope, each of which will consume one "site" in the license.
To do this, navigate to Periscope in the browser and go to Settings (gear at the top right of the page). This will take you to the About settings page:
Then click on the "Choose Sites" button to select which sites are usable by Periscope.