The dev team went out "into the field" to help roll out the software to the company. This also allowed us to see how others used the software.
At the end of the day, one of the devs reported back that one personal assistant would maximize the email app's window (back when 17" CRT monitors were large) and after each email was processed, she'd print out the email and file it the appropriate spot in a filing cabinet.
All the devs were, "But... But... she can just file the email in an email folder in the program. Why does she need hardcopy? Email was supposed to save trees!"