I was on a DTW-KIX-ICN free flight on NW/KE...NW oversold the DTW-KIX segment and offered me a nice $750 voucher and upgraded me C class DTW-NRT-ICN all NW. i got the miles posted on my account and the C class bonus and the elite bonus. after about a month, the mileage was withdrawn! i guess someone at NW realized that the C class flight wasn't a paid one. oh well...sometimes you get lucky and other times you don't.