Good news for the Android developers: Google has announced that the Play Store is finally offering support for promotional codes. This means that the app creators can now offer promotional codes that will allow the users to perform free downloads or free in-app purchases. Since Apple's App Store already provided this functionality for some years, it was about time that the Android market started catching up. This news isn't only important for the developers who now have a better tool to promote their applications, but also for the users who can receive free content.
According to the information made available by Google on its help pages, developers are limited to as many as 500 codes per quarter, so they can't overdo it. The same pages also offer a few suggestions to the app creators about how these codes can be successfully used to achieve their goals: giving out in-game items to the clients who attend specific events, distributing promo codes for an app at a local business, etc. If the app in question already embeds In-app Billing version 3, then implementing promotional codes should be really easy. If not, it's a little bit tricky, but Google's help page gives you all the information that you need.
It seems that Google is really making an effort to catch up to Apple's App Store. Besides this latest announcement, a couple of months ago the Play Store added support for the Family Sharing feature. Furthermore, the company also stated that very soon, its app store will make ad-supported items easier to spot, so things are definitely heading in the right direction.