A Playbook for Improving Customer Journeys from Adaptive Path – this is a nice overview of what the impact of a journey map can have – looking for “troughs” (negative experiences) for example

“You can’t just stop after creating an experience map. That’s because a good current-state experience map is simply oozing with potential: the potential to create an even better experience. But how do you move forward? How do you see the opportunities? Well, it’s a little easier when you know what to look for, what the patterns of success are.”