When they use the term "revenue dilution" they are referring to the flexi pass program that US West currently has. Under this program, US West employees are given up to 10 flexi passes per quarter, based on attendance. It takes 1 pass for a rt buddy pass (this is the revenue dilution, more later). 2 passes to pay for parent travel round trip. 2 passes for companion travel, etc. 1 pass for a one way upgrade. These passes have expiration dates, but if ticketed prior to the expiration date, the buddy pass ticket is then good for one year from date of issue.
Flexi passes are so widespread and quite expensive to use. For example a round trip fare on a flexi (buddy) pass is near $200.00 rt PHX-PHL. Because it's expensive, and because employees receive such large amounts of them, they are given to just about anybody that will take them (unlike the newer pass, where the employee will have to be far more selective as to receives them). With this said, the company believes that many people that ended up with a flexi in their possesion, use it for the flexibility of the standby travel and not the need for discount travel, therefore they are often times a full fare passenger except when they think they would rather have flexibility. So in a nutshell, many of these people could essentially pay another 75.00 for a confirmed seat, but choose flexiblity over confirmed.