I only fly NW every 6 weeks or so since they have decent priced MDW-MSP flights. The AA option out of ORD is to $$$$. Anyway, flew up to MSP this week and got 500 miles for the flight, 250 for turbo miles (outbound on 2nd RT), and then an extra 250 "BONUS MILES". What could this be for?

I have an entry for non-flight activity of 1000 miles for Northwest E-Commerce - Online Booking so I do not think the extra 250 was for buying online.

This should be my qualifying activity for FFF2, already have trx 1 SPG point and have 2 Hertz rentals post - waiting for 2 Hilton stays to post from a few weeks ago to get the 10,000 bonus miles. Once I get that, I should be a hair shy of 25,000 so these mystery 250s might help me get over the top.