Promo codes aren't new in the Play Store. Google has been using them for a while to redeem apps (like the free family apps it offered for a few weeks) and other types of media. However, the option for developers to generate their own codes and issue them to their users was only added a few days ago.
Google's documentation details how developers can create promotions, what they need to do to set them up in their apps, and how users can redeem them. Here is what the process looks like in the Developer Console and on the user's end.Read More