Amazon has launched its Amazon Coins virtual currency in the US, with a free $5 worth automatically deposited in the account of every Kindle Fire owner.

The money is much like Microsoft's Xbox Points, in that it can be exchanged for games, apps and in-app purchases on Kindle Fire tablets. Coins are bought from Amazon with real money, but with the electronic retailer offering discounts of up to 10 per cent when they are bought in bulk, it could reduce the cost of putting content on to their devices.

One of the main reasons for Amazon to adopt a virtual currency is to make it easier for customers to make in-app purchases and to have the money come straight out of their Amazon accounts rather than have to submit credit card details to individual app developers.

Developers will earn their usual 70 per cent revenue share when accepting Amazon Coins.

"Today we are giving Kindle Fire owners $5 worth of Coins to spend on new apps and games, or to purchase in-app items, such as recipes in iCookbook, song collections in SongPop or mighty falcon bundles in Angry Birds Star Wars, said Mike George, vice-president of Apps and Games at Amazon. "And with discounts of up to 10 per cent when you buy Coins, this is a great way for customers to save money.

"We will continue to add more ways to earn and spend Coins on a wider range of content and activities - today is Day One for Coins."

It is understood that Amazon is considering introducing Coins to other markets worldwide, but is likely to use the US as a test bed first. Don't expect anything too soon.