Community Coupons are coupons given out as rewards for users participating in activities in the Steam Community. Currently they are used as rewards for crafting sets of trading cards into badges; for more on that read about Steam Trading Cards
We'll try to answer the most common questions here, but if you have more please post your question to the Steamworks Development Group
How do Steam users get granted these coupons?
Coupons are granted as part of turning a set of Steam Trading Cards into a badge. You can read about the Steam Trading Cards feature at http://steamcommunity.com/tradingcards/
How do you decide which coupon a user gets?
A coupon is selected at random for a user, excluding coupons for games they already own. Right now it's an even distribution; but we'll be changing it select coupons that are more likely to be redeemed, based on their current redemption rates.
How do we measure success? Coupon drop, trade, & redemption rate?
There is a 'Coupons' link at the top of the financial site that will show you all existing coupon activity.
Can coupons be stacked with other coupons or discounts?
No, the coupons cannot be stacked with other coupons, and coupons cannot be stacked with any discount or sale price.
Can we add other discounts or frequency rates?
No, they are fixed in the system.
Can coupons be sold in the Steam Community Marketplace?
No, coupons cannot be bought or sold by users.
Can coupons be traded between users?
Yes, coupons can be traded to users (this frequently happens as a way to give a coupon to a friend).
Do I have to create the assets for the coupons?
No, the coupon images and text are generated automatically.
How long are the coupons valid for?
The coupons are valid for 14 days after they are initially granted. We have found this to be the best duration based on prior experiments with coupons.
How do I opt-in to giving out Community Coupons?
From the navigation above, select 'Apps & Packages', find your game and click on the 'App Admin' link, then under the 'Community' tab select the 'General' sub-menu. At the bottom of that page is a checkbox to opt-in to the program.
How do I opt-out of the Community Coupon program once I've enabled it?
You can opt in or out of the program at any time. Like above, just uncheck the Community Coupon program checkbox on the admin page for your game, and publish the change.