Amazon has added a way for developers in much of the United States to make money selling products from Amazon within their mobile apps.

The new Amazon Mobile Associates API is currently only available for Android, including Kindle Fire. Using it you can sell real products from Amazon, whether physical (such as toys or clothing) or digital such as eBooks.

When you sell an item, you’ll earn up to six per cent in advertising fees from the purchase. The Mobile Associates API is an extension of Amazon Associates, the web-based affiliate program that pays advertising fees when purchasers click through from websites.

The announcement of the new API suggests several ideas for how this might work, including selling single items or showcasing categories of goods that are somehow relevant to your app. Another options would be to bundle a purchase of a physical product from Amazon with digital content within your app: Sell a toy version of one of the characters in your game, then automatically enable them to play as that same character.

This video outlines how it could increase revenue from apps:

The way it works is that if a customer starts the process of making a purchase from within your app, they are presented with a dialog box showing the product details and cost, and can then complete the purchase using Amazon’s 1-Click purchasing. The items will be shipped directly from Amazon to the customer, and you’ll earn up to six per cent of the total purchase, added to your app distribution earnings.

To add the integration, you initialize the Mobile Associates API, tell Amazon what you’re selling using either a specific set of ASINs (Amazon Standard Identification Number), search terms, or use the Amazon Product Advertising API to query a list of ASINs and product information. Complete the purchase information, and the API handles the rest.

Currently the API is available only in the US and excludes several states where the Amazon Associates program is not available. The Amazon Mobile Associates API page lists the restrictions and has a Quick Start Guide, sample code, documentation together with the download link for the SDK.