I just received from NW, where I'm top tier, the offer of 1500 miles for $150 in dines by March 31. I need to consider that I've registered for DL, where I'm a basic Online Member, and their 1000 for $100. Questions come up of what happens if I merge my miles in the two programs for the 500-mile bonus that's offered for that: a topic for another thread, I guess.