I got a PU on a recent MEM-AMS flight, V fare basis, published ticket. Previous "attempts" on unpublished (but more expensive) tickets did not come through. I checked the standby/upgrade list and never was listed. At boarding, my boarding pass beeped and the agent, a bit confused, said my seat assignment had been changed. Best part was a NW Gold colleague in another PNR but linked to my reservation also got the PU! I think only 1 or 2 others got the PU. Economy was almost full, only a handful of empty seats. Sweet treat, thanks NW. ^