This tool allows you to easily configure UTM (Urchin Tracking Module) parameters to URLs so you can measure custom campaign in Google Analytics.
It is common to ask why we should use an URL tracked by UTMs. This is the acronym for Urchin Tracking Module, that represents a bunch of parameters used right after the end of a common URL to understand what was the contact point to the users in a specific link.
Long story short, the job of UTM is established the necessary tracking parameters to Google Analytics and others tools read and compute the data.
With this you can see and monitor the traffic to each link and make a complete analysis to channels used in your marketing campaigns. The specific results of each campaign are clearer from the source of traffic. That way you can identify which marketing campaign is performing the best.
See some examples or ideas of using UTM to measure your performance: