20K Bonus Play? A-OK! Once again, Northwest WorldPerks is offering a chance to earn bonus miles through both Northwest and partner activity. Members earn set numbers of miles for various activities — from flying to renting a car to staying at a hotel. Once a member reaches 10,000 miles, he or she will get an extra 10,000 on top of that, for a total of 20,000 miles. Registration is required, and the promotion ends Sept. 30. Check out http://www.nwa.com/offers/20Kbonusplay for details.