Northwest WorldPerks members who shop at participating merchants at the WorldPerks Mall could win enough miles for two award tickets from the U.S. to Europe. Register at http://www.nwa.com/offers/backtoschool2007 prior to shopping and shop through Sept. 30, 2007. The member who spends the most amount of money during the two months will win 100,000 bonus miles. Merchants participating in the back-to-school shopping spree include Bagsbuy, Barnes & Noble.com, Brookstone, Charles Tyrwhitt, Cooking.com, Dell, Disney.com, eBags, ESPN.com, Footlocker.com, Hammacher Schlemmer, Harry and David, HP Home and Home Office, MacMall, Magazines.com, Montgomery Wards, New York & Company, Nordstrom, Office Depot, OfficeMax, Sears, Shoebuy, ShopNBC, Sony and Timberland. Merchant gift certificate purchases will not qualify for the promotion.