Joey:
There is no way to know what the start date for this promo was without calling CO and even then I wouldn't count on their answer. CO appears to be even sloppier than usual with this promotion with no start date, no statement about if it applies to CO EXpress, CS, or to flights on NW with or without CO codeshare numbers. They seem to be getting worse with the layoffs at OnePass and in Marketing they have had.