Northwest Airlines is offering a generous bonus for shopping through its mileage mall portal–up to 10,000 bonus miles for shopping with 10 different merchants through June 30, 2009. WorldPerks members can earn 1,000 bonus miles for each purchase made with a unique merchant and the bonus miles are in addition to the standard mileage offer. The bonus miles are only offered once for each merchant and multiple purchases with the same merchant will not be eligible to earn additional bonuses.

Over 50 merchants are participating in the promotion, including Borders, Bliss, Harry & David, macy’s.com, Rosetta Stone and TravelSmith. Registration is not required and a maximum of 10,000 miles can be earned through this offer.

For more information about the promotion, go to www.insideflyer.com/link/?1579. FlyerTalk members have discovered some of the best ways to take advantage of this offer by completing low-cost transactions such as buying $1.29 nail polish at drugstore.com or purchasing a screwdriver at Sears for $.99 and picking it up in the store. To view more ideas, visit http://insideflyerus.wpengine.com/link/?1578