A Bet: 1,000 SkyMiles if You are Not Yet a Delta Air Lines SkyMiles Member
If you are not a Delta Air Lines SkyMiles member, you are in luck.
You have until April 15, 2007 to earn 1,000 bonus SkyMiles when you sign up as a new Delta Air Lines SkyMiles member.
Additionally, in a separate promotion, simply sign up and use your American Express® Business Card to book any Delta Air Lines flight between January 15, 2007 and April 15, 2007, and you will earn 5,000 bonus SkyMiles.
More details can be found here.