I experienced the new computerized standby system for the first time last Friday at LAX. Except for irregular ops when they may waive the upgrade charge, I think it is less likely to skate by without paying the upgrade to Y with the computerized system.

When I asked to go on the standby list for an earlier flight, the gate agent asked for my credit card indicating they swipe the card at the time you are added to the (computerized) standby list but only charge the card when you are actually given the boarding pass for the standby flight.

I didn't make the cut and the gate agent did a PA announcement that the flight was full and the list would rollover to the next flight (at a different gate). Although the other standby PAX left the gate area, I hung out, waiting to see if all 137 checked in PAX were actually on board. Sure enough, the ops agent advised the gate agent there were two missing (people who had checked in on-line but were no shows). The gate agent asked if I still wanted to go, then gave me a new BP when I nodded yes. There were still people in the jetway as I went to board... and before I got to the plane door, the agent brought me the upgrade credit card chit to sign... no skating this time.

My conclusion: if swiping the credit card at the time you are added to the automated standby list is the new protocol, except for delays on your scheduled flight, it is less likely the upgrade fee will be waived, and a more reliable source of additional revenue is created for WN.