Google finally allowed app developers for Android-based devices conduct promotions in Google Play and distribute promotional codes.
In support of the developers has a description of how to create and manage promotions. As a result, developers can generate promo codes for paid content in the app and the paid app. For subscriptions and inactive content to use the promotional code cannot.
For one application, you can create up to 500 codes per quarter. Users will be able to use promotional codes in Google Play before the end of the promotion, the duration of which is controlled by the developer.