Groupon is offering $5 of free Groupon Bucks on their Facebook page. Just head over here and like their page if you have not already, and then click on the Freebies tab. You’ll receive a unique code which you can redeem in your Groupon account for a free $5 credit.
Head over here to get your free Groupon credit.
Update: Looks like all the freebie codes have been claimed.