Amazon is launching Amazon Coins, a virtual currency to purchase apps and buy in-app goods on the Kindle Fire. Announced this morning, Amazon says they will be available in May.

According to the Amazon Coins FAQ, an Amazon Coin has a one-to-one relationship to an American penny, so developers will receive the same royalty payments as credit card purchases. Users will be able to purchase everything but subscription-based services.

At May’s launch, Amazon promises to give away “tens of millions of dollars worth of Coins” to customers. Amazon is investing significant money in the giveaways, but users will need to purchase a Kindle Fire to redeem their gift or, at the very least, visit the Amazon App Store and risk purchasing more than just what the Amazon Coins are worth.

Furthermore, we can imagine future Amazon gift cards not being redeemable in the entire Amazon marketplace, but tailored, via the Amazon Coin, to be redeemed just within the Amazon App Store.  The Amazon Coin is another serious run to lock users into the Amazon ecosystem, specifically the Kindle Fire one.

Amazon has certainly been looking at Facebook’s issue with its own Credits system. As Inside Facebook reported in 2011, Facebook eventually let developers use their own in-app currency systems because the translation between currencies was too confusing.

To be involved in the launch, app developers must sign up for Amazon Coins by April 25. Amazon Coins will only be available in America at launch.