Just got this today:
To get a 500 mile Skymiles bonus call (800)558-3358 (enter code # 2089) or visit
www.delta.com/bonusmiles
All you have to do is register by Friday and fly one time before April 15.
However, my fiance's number (she's a FO and I'm a GM) would not take so perhaps it's targeted.
Good luck!