One of the key advantage of running your own bank is that if the mood - or need - arises you can just print more money.

So (perhaps) following the lead of the US and UK central banks, Amazon has decided to encourage users of its Appstore to fill their wallets with cheaper money.

Until 19 October, you can purchase $5-worth of Amazon Coins for $4.60, $10-worth for $9, $25-worth for $21, $50-worth for $40, and $100-worth for $80.

In keeping with Amazon's vertical ecosystem, the coins can be used to buy apps or make in-app purchases on Kindle Fire, Fire phone, Fire TV and Amazon.com, as well as being gifted to others.