The Flipkart PHP SDK by Saneem unofficially interacts with the Product Feeds API. It provides authentication and callbacks. A live demo is available at http://www.clusterdev.com/flipkart-api-demo/demo.php
Listrak is an email marketing company solely focused on the ecommerce channel. By getting to know their clients in depth, reviewing clickstream data and transactional history, and plotting customers on a lifecycle grid, Listrak is focused on delivering two things, according to CEO Ross Kramer, "help our customers acquire more new customers, and sell more to existing customers." The Listrak SOAP API makes automation of managing email campaigns easier.
TipTap Lab uses psychology to better understand existing and potential customers. The TipTap Lab API allows third party apps to take advantage of such psychology by building profiles for those that interact with the app and acting accordingly. Whether an app developer wants to personalize an online experience or pair up users with similar interests, the TipTap Lab API examines the abstract, subconscious layer of users to better and enable a developer to accomplish goals.
The RESTful Asos API (with JSON responses only) from UK-based Asos integrates access to a massive fashion catalog with over 50,000 product lines growing at 1,500 lines a week, in womenswear, menswear, footwear, accessories and beauty.