Northwest Airlines continues to offer these very brief lessons on the advantages of Worldperks, Northwest Airlines frequent flier program. If you have not done so already, I highly recommend you take these courses and earn yourself a few hundred bonus miles.For each course, read a short description of a product or service Northwest offers, answer three (simple) questions and earn 100 Northwest Airlines Worldperks miles. Five courses are currently available. Click here to study and take your quizzes.