The Best Buy Developer site offers tutorials to work with Products, an API that provides REST protocol to access product's pricing, availability, and images. The tutorials are under the how to's category and the topics include search for products based on description, search based on review criteria, and search based on a list of attribute values. Keyword search is also available. Something to consider, Best Buy product information is updated close to real time with the goal to facilitate product search for developers and consumers.
eBay completely revamped its API portfolio to create a seamless experience across the eBay developer experience. The launch includes 10 APIs in total, on both the buy and sell side. The APIs replace some legacy APIs and include a number of completely new features for enhanced integration.
Here is a follow up interview with Raj Kadam, CEO of Viralheat API whom we have interviewed on the Sentiment Analysis API here. In 2012, Viralheat had about 30 billion calls over all its' APIs. Viralheat just announced a new API called Human Intent API.