The actual amount of revenue earned per customer, taking into account materials and promotional costs is -$6.
First step is to find the customer acquisiton cost
Customer acquisition cost=Amount spent/Number of new customers
Customer acquisition cost=$2,800/50 customers
Customer acquisition cost=$56
Second step is to calculate the amount of revenue
Amount of revenue=$50-$56
Amount of revenue=-$6
Inconclusion the actual amount of revenue earned per customer, taking into account materials and promotional costs is -$6.
Learn more about revenue here:https://brainly.com/question/16232387