Shopping APIs and mashups are to this era of the Internet what retail eCommerce was to the early Web in the late 1990's. It is one of the earliest and most successful uses of open web APIs to date with over 25 shopping-related APIs and 300+ shopping-related mashups listed here at ProgrammableWeb.
In this overview we'll introduce you to the spectrum of e-commerce APIs available, the various sub-segments within this space, the different revenue models, and then review the types of mashups and applications developers have built on top of these APIs.
It was eBay who in 2001 first began offering an external web service API and thus created a programmable auction platform. The service has been so successful that today almost half of all product listings on eBay are created using tools that leverage the eBay API and they process over 3 billion API calls per month.
In 2002, not long after eBay's API launch, Amazon.com introduced their E-Commerce Service (ECS) API. This API offers developers the ability to search through the millions of products in the Amazon catalog, add items to shopping carts, and ultimately share transaction revenue using the same model as Amazon's affilate program.
Beyond these two leaders, shopping-related APIs come from a variety of large and small vendors. Some like Amazon.com's provide access to online retail catalogs such as the GoodStorm API. Others like SwapThing facilitate bartering ("my thing for your thing" as they say). Some services that allow you to create customized products, also known as on-demand manufacturing, offer APIs including CafePress and Zazzle.
In the world of classifieds listings, two APIs to consider are the Google Base API and the Windows Live Expo API. Each of these provides access to millions of classifieds listings ranging from garage sale items to new and used vehicles.
Another class of APIs are designed to facilitate product search and comparison shopping. Three good examples include the Shopping.com API, the CNET API, and the Yahoo! Shopping API. Each of these APIs provide access to millions of products offered by thousands of merchants.
Once products have been found, there are a few APIs that can aid in the process of getting them through checkout and paid for. Paypal, the classic online payment service offers their own widely used Paypal API. A newer entrant here is the Google Checkout API which lets merchants integrate credit card payments while allowing customers to use their own Google identities. And finally, services like PaySimple and Authorize.Net API can be used for payment gateway services enabling web-based merchants to authorize, settle and manage credit card and electronic check transactions.
Not all APIs in the shopping category are designed to give you access to a database of products, but instead they play a supporting role in the shopping process. For example, the buySAFE API, a type of bonding service for ecommerce sellers intended to increase sales by guaranteeing transactions (they initially started at eBay but now bond transactions at a wide variety of small to large etailers). The API could potentially be integrated into any shopping mashup application as a means to increase conversion rates. The Zixxo API is a shopping coupon service that gives you access to their services for creation, management and syndication of coupons. There's also the UPC Database API, a very simple XML-RPC interface into this free database of UPC and EAN product codes (note this is a non-commercial site, run only as a hobby).
In addition to their E-Commerce API, Amazon.com also offers developers access to over three years worth of actual sales data for books, music, videos and DVDs via their Amazon Historical Pricing API. Use this fee-based service to make decisions based price trends like average, minimum and maximum prices. Now if you're more interested in analyzing trends in auctions you can use the DataUnison eBay Research API, a fee-based service that gets you price and sales trends but also gives you auction-relevant data like total listing time.
How are shopping APIs monetized for the provider and the developer? Some are Pay-Per-Click (PPC) such as Shopping.com and Yahoo! Shopping where merchants pay the API provider a fee for each user that clicks through and a percentage of that fee is then shared with the developer. Others are Pay-Per-Action (PPA), such as the Amazon E-Commerce API wherein an affiliate revenue commission, often between 4-8%, is shared when a referred user purchases a product. In support of PPA-style models is the Commission Junction API that allows advertisers and publishers to manage affiliate relationships.
Other APIs offer their own models. For example, using the buySAFE API is free because use of their API leads to more direct revenue for their core business (which for eBay sellers are charged 1% of the sales price and elsewhere the buyer pays). GoodStorm does a revenue sharing of 50% of the profits, SwapThing who charge $1 per swap, and Zazzle gives a 17% commission of net revenue actually received for every qualified sale (10% royalty fee plus 7% referral fee).
Hundreds of shopping mashups exist ranging from commercial desktop applications to comparison shopping web sites to whimsical hacks. We'll break these down into a set of shopping mashup categories that let us get a good picture of this world.
Comparison shopping mashups use open APIs to gather data from multiple sources to provide new ways to compare and contrast similar products across merchants, brands and sites. Success stories include Chitika Mini-Malls who build on data from the Shopping.com API. VC-funded startup Mpire use APIs from Amazon, Shopping.com, eBay and others to create a unique comparison service. Other examples: SecretPrices.com. Comparison tools can also come in the form of browser plug-ins as with Blue Organizer, a Firefox plugin from Adaptiveblue. They have analyzed over a trillion transactions. APIs open the doors to specialized comparisons like Game System Wars that use the Amazon and Google APIs to track the XBox, Wii and PS3 competition, and PrinterComp to price and feature compare new and used office furniture.
Shop by seeing things in a unique way. That's the idea behind most visualization-style shopping mashups. You can find shopping visualizations by searching on the tag combination shopping + visualization.
Examples include amaDig for Amazon shopping or get a rich visual map of related products with the Flash-based Similarity Web. One of the all-time best has to be CoverPop that combines hundreds of similar Amazon.com product images into a single interactive page. Innovative, fun, and even lets you buy what you see. FeatFinder is a mashup contest winner that lets you explore relationships between artists in a six-degrees of separation way as does The Amazing Baconizer, and the Relate-a-zon Game. Flowser is a graphical Amazon browser. LivePlasma is another way to see and interact with the relationship between movies, bands, actors and others (and TuneGlue also integrates the Last.FM API). Click on any of the thumbnails below to get a full profile.
This category harkens back to the some of the initial reasons for eBay opening-up their APIs: grow the auction network by making the process of creating new auction product listings easy and efficient. The eBay API enables this by providing a means for third-parties to create tools for power-sellers. These tools include Infopia, bidmachine and Terapeak.
Developers around the world have created shopping mashups for their part of the world. Joybeans Shopping is a simple Japanese shopping site power by Rakuten API. For buying a car in the UK you can use quertycars that combines Google Maps UK with eBay motors autos. Find German eBay auctions with Shoppingmap Germany. The UK Tesco Store Locator is built with Microsoft Virtual Earth maps. BookJetty let you shop from Amazon along with data from the Singapore National Library Board catalogue.
Niche shopping segments created from broader or multiple sources. Cars and other vehicles: Car Trader, eBay Motors, Find a Convertible Car, qwerty cars, and Motor Map USA. iPod Radar helps you find everything iPod, Hiking Outpost is a hiking and camping destination that integrates Amazon.com product data. Wii Seeker that helps you find Nintendo Wii game consoles. CameraPrices.com uses the Shopping.com API to fetch photo-related items while CamChoose.com uses Amazon, eBay, Shopping.com and Yahoo Shopping.
Use mashups to get shopping advice or perhaps to shop with your friends. Wishpot is a mobile/social shopping service using the Amazon and Shopping.com services that lets you save and share things you find online or in stores. Pleo, the robotic dinasaur, has a community at Pleo HQ that also pulls-in data from Flickr, delicious, YouTube and eBay. Other examples include an MSN Messenger extension Shopping Together that lets two users shot via their chat session, Passado.com user recommendations integrate with Amazon and MusicBrainz APIs, while Yelp is a leading user-driven review site with reviews of stores, restaurants, bars and venues placed in context on a Google Map. For a more specialized example see Jargol Shopping Guides that let users rate local boutiques.
Life2Life is a real store in a virtual world that lets you buy products form Amazon.com from inside Second Life. Giveness enables non-profits to raise money by selling through Amazon and eBay APIs. My 10 Wishes is a contest winner that lets children pick what they want for Christmas. Mashed Tickets lets you compare concert, sports and other event tickets from multiple sources including eBay and StubHub. Or, on a different note, if you ever had problems ordering camera supplies from a camera vendor in NYC then the NYC Camera Shops Map might be of interest -- it plots the locations, along with photos and comments, of dozens of vendors (and not always reputable ones).
There are lots of examples where ecommerce is combined with a geographic context and integrated with a mapping API. Auction Mapper for eBay shows you where listed products come from as does BidNearBy. Note that most of the International Shopping examples above integrate maps and shopping. Superhighstreet.com are virtual tours of real streets in London.
Some mashups give you access to the power of web-based shopping even when you're not on the web. Take for example Comparison Price Shop by Phone, Price Compare by Phone, SCANBUY and Frucall which get you access to the Amazon.com catalog from your mobile phone. A handy tool when you're at a store and wondering if a certain product might be a lot cheaper online. For eBay bidders there's UnWired Buyer.