Delta SkyMiles and Northwest WorldPerks members can earn up to 25,000 miles with a new “Pile on the Miles” partner promotion. Through June 22, 2009, members can earn bonus miles for completing valid non-flight partner transactions, such as staying at a hotel, renting a car, taking a cruise or redeeming e-Rewards currency for miles.

Complete four unique partner activities to earn 4,000 bonus miles, six activities for 6,000 bonus miles, eight activities for 8,000 bonus miles, 15 activities for 15,000 bonus miles and 25 activities for 25,000 bonus miles. Each partner activity will only count once toward the promotion, but you can repeat activity with different partners within each category for additional credit. For example, if you stay at a Marriott, InterContinental and Hilton hotel during the promotion, you’ll receive credit for three partner activities. Stay at a Doubletree, Embassy Suites and Hilton, however, and you’re three stays will only count once because Doubletree and Embassy Suites are both Hilton Family brands.

Registration prior to completing any partner transaction is required and for WorldPerks members, the offer is only available to members residing in North America and the Caribbean. All SkyMiles members are eligible to participate. The bonus miles are in addition to the standard mileage earned through partner activity. Flight activity on Northwest, Delta or partner airlines will not qualify as valid partner activity.

Register and view the list of Delta SkyMiles participating non-airline partners at http://insideflyerus.wpengine.com/link/?1586 and Northwest WorldPerks registration can be found at http://insideflyerus.wpengine.com/link/?1625