Try the TrivialDrive sample app at https://github.com/googlesamples/android-play-billing to get started!
Freemium is a product pricing strategy where instead of charging the user for the app download, you make money on in-app purchases or even upsell the user to a subscription. In this video, Jarek Wilkiewicz will show you how you can implement freemium using the Google play In-app Billing API.
For more information about In-app Billing API, visit: https://developer.android.com/google/play/billing/billing_overview.html.
To learn about different monetization strategies check out the “Develop a Sustainable Financial Strategy” course on Udacity: https://www.udacity.com/course/app-monetization–ud518. The 2012 – 2014 IAP revenue projections in this video were provided by App Annie, you can find more information in this blog post: http://blog.appannie.com/mobile-app-advertising-and-monetization-trends-2013-2018/.
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