Listening to: Nothing.
I am working on a new Facebook game called UPC Hunter. The premise of the game is very simple: a collecting game where you amass as much fortune by discovering treasure. The kicker is that treasures are found by entering UPC codes on the back of normal objects like photo paper, glue or even a can of soda.
The game currently only supports 12-digit UPC numbers. You also can't just enter any UPC code as it must follow the formula that is employed every time a cashier scans items for you at the store (you can find this via a google search).
So what's to keep someone playing?
1. Every UPC code generates a random item (out of roughly 150+ items). However, even if you generate an item you've generated before (i.e. Boots of Escaping), the value will be different.
2. Inputting a UPC that has been previously entered decreases the value of the object to your specific discovery. So if you sit there and keep inputting your Best of Both Worlds Concert: The 3-D Movie: Extended Edition DVD, the value you obtain will continue to be divided by how many copies of that treasure were found. Thus it pays to enter something new.
3. It will record who was the first one to discover a treasure, thus spreading your notoriety.
4. There are achievements.
5. It's just fun to see what item you'll get from a UPC code.
6. Though not the first usage of UPC codes in some kind of game mechanic (see: Barcode Battler), there aren't any applications like this readily available.
7. There are also special treasures that get generated if a specific UPC is entered. I'll hide these in the game and they're also "fun" to discover.
Should be released soon. I'm predicting end of next week.