Bit.ly is a URL shortening service that allows users to track clicks on shortened links. It provides metrics in real-time on link clicks. While a user can only generate one shortened link per original URL, adding additional code to the end of the URL will make it unique and allow generating multiple shortened links to separately track clicks from different mediums. Metrics on link clicks can be viewed by adding a "+" to the end of the shortened Bit.ly link or through the dashboard. Bit.ly metrics also show hourly and daily click data and can track clicks from other shortened links pointing to the same page.