At the time of writing, it was named Potential but now it's named Priority. The meaning has stayed the same though. What I tend to do is focus more on the Organic CTR because if the Monthly Volume has "no data" it will make the Priority score very low. You can change this by applying your own modifier in "My Score" but it depends on what your Potential cut off is. E.g. I won't target any keywords under a Potential of 40.