Unlike some chepo flyers, I think UA SWUs present great value. Namely because of the # of destinations UA flies to, and in particular the ability to use them on LH to go from C to F. if your employer already pays for C, this is golden. (Getting a TA to ticket and expense a non Z fare is another story) In the end, it does present some savings, and is a nice reward for some of us who practically live on United aircraft, and fly so much. (sometimes, unnecessarily). Unlike AA's instruments, you cant use it to from BA Club World to BA First.... The key for using UA SWU of course is NC and NF inventory. I've been monitoring the availability of this internationally (this doesn't really apply to domestics) and I can't seem to nail down a pattern of when and how inventory of NC and NF (again, internationally, is released) . The pattern is very much, random. - Is this done, via a secret algorithm, automatically? - Is there a route analyst that determines what to release? Anyone have wisdom on the above.