Amazon will launch a virtual currency dubbed Amazon Coins for in-app purchases on its Kindle Fire. Why? It's all about courting developers and luring them with engagement and money.

At Amazon's cloud customer powwow late last year, the company went out of its way to tout engagement and monetization on its Kindle platform. The not-so-subtle message: Developers on Amazon's platform can monetize better than they can on Google's Play Store and roughly on par with Apple's App Store.

The company said that Amazon Coins will launch in May and only be available in the U.S. at first. Amazon plans to give away tens of millions of dollars of free Amazon Coins to pad developer wallets. Amazon Coins will likely be acquired throughout the e-commerce juggernaut with a click or two.

Developers have to submit their apps by April 25 to be in the program.

What's the end game for Amazon? For developers, there's some linkage to Amazon Web Services, a venue for creating games and apps, and the Kindle Fire-led Appstore. Ultimately, Amazon may garner exclusive apps should it be able to prove engagement and monetization for developers over time. Typically, developers go for Apple's iOS first and then Android. Amazon wants its Kindle platform in that discussion.