Sometimes the goal of a campaign is not a purchase, but a micro-conversion prior to that. A Winback's goal is re-engagement, for example. You can change the conversion measurement when measuring the impact of a touchpoint.
Change the Attribution Conversion and Time Window
When you change the conversion event, it's important to know that since not all events have revenue (pageview, sign up) that the revenue metrics may drop to zero when changing the conversion. By default, the conversion is set to be for Orders and a 3-day last engaged model
Here is how to change the conversion for reporting.