Delta is offering bonus miles for booking multiple tickets at once online. Registration is required.

SkyMiles members can earn bonus miles on all Delta, Delta Shuttle®, Delta Connection® carrier or Song® flights, for every flown round-trip ticket purchased at delta.com using your American Express Card and flown between January 1, 2006 and December 31, 2006. For transactions including 2 tickets, the purchaser will receive 1,000 bonus miles. For transactions including 3-4 tickets, the purchaser will receive 2,500 bonus miles. For transactions including 5 or more tickets, the purchaser will receive 5,000 bonus miles. To qualify, tickets must be purchased on the same itinerary.