I'm putting the text here to make it easier for people who got this post card to find it:
6025 Sandy Springs Cir NE # 318
Atlanta, GA 30328-3863
Pin # 0650197417
"We Have (Insert Smiley Face Here) Good News"
Dear John (Or whoever you are.)
We are trying to reach you with good news! It is real important that you call toll free 1-888-279-9221.
Call 12 noon to 8 pm EST
Monday thru Friday
From what I've read online there are a lot of these post cards going around with varying catch phrases including "we've been going nuts trying to contact you" with a picture of a couple nuts running around.
If they can get you to call, they try to sell you magazine subscriptions so you can enter a contest of some sort. From what I can tell these people aren't too malicious. But I wouldn't waste my time calling.