The listing, Facebook Credits - Two Cap Codes Worth 1 to 5,000 Credits Each has ended.
We have two green soft drink caps with codes for Facebook credits that will be emailed to the winner at the conclusion of this auction. Every bottle (cap) is a winner and each code can be worth 1-5,000 credits.
From https://www.facebook.com/credits/ :
What are Facebook Credits? Just like tokens at an arcade or amusement park, credits are a secure way to play games and buy virtual and digital goods on Facebook. You can use your credits across any supported games and apps on Facebook.
More details and redemption here:
https://apps.facebook.com/flavorcodes/
The fine print states you must be a legal resident of 50 U.S. states or District of Columbia and age 13 or older. Redeem by 11/30/13. Limit of three codes from purchases or free requests can be redeemed per day.