Amazon.com Inc. has unveiled a new way for app and game developers to make money through the e-retailer’s line of Kindle Fire tablets—Amazon Coins, a virtual currency for purchasing apps, games and in-app items on a Kindle Fire.

Amazon Coins is an easy way for Kindle Fire customers to spend money in the Amazon Appstore, offering app and game developers an opportunity to drive traffic and downloads and to make money from their apps, Amazon says. When Amazon Coins launches in the U.S. in May, Amazon will give customers tens of millions of dollars’ worth of free Amazon Coins to spend on developers’ apps on Kindle Fire in the Amazon Appstore. Amazon says it will make it quick and easy for customers to buy additional Amazon Coins using their Amazon accounts.

Amazon Appstore developers will earn the standard 70% revenue share when customers make purchases using Amazon Coins. Developers with apps and games currently in the Amazon Appstore for the U.S. don’t need to do anything with their apps to capitalize on Coins, Amazon says. Developers not yet in the Amazon Appstore should submit their apps soon, Amazon says, as only apps submitted and approved by April 25 will be ready when Kindle Fire customers have Amazon Coins to spend at the Amazon Appstore.

When asked how much Amazon Coins would cost, how they would be easier to use than an Amazon account, and how consumers will store and track their Coins, an Amazon.com spokeswoman declined to comment and said only that the e-retailer will be announcing more details when Coins officially launches in May.

Some app developers briefed by Amazon are upbeat about the new Coins program.

“Everyone recognizes Amazon’s success in the e-commerce world—now the Amazon Appstore has become a major player in the mobile app marketplace,” says Misha Lyalin, CEO of games app developer ZeptoLab. “Amazon’s new virtual currency is designed to open new opportunities for developers and make things easier for customers. This is a great example of Appstore innovation and we want to support it.”

On a related note, Amazon, No. 1 in the Internet Retailer Mobile 400, recently announced in-app purchasing for Mac, PC and web-based games, enabling developers to let customers use their Amazon accounts to purchase virtual goods and currencies from games on those platforms.