Here's an awesome image from the current progressive Facebook challenge of Limited Runs. To start, you buy a stamp for a $1 and then as long as you participate in the challenge you will receive the next stamp for free. You could also win the challenge and get an additional prize in addition to receiving the stamp for the new challenge.
I just love this cute santa, I thought it would be a lovely Christmas card for December. Check out this company on their Facebook group-- Limited Runs Stamps.