What do you get when you use APIs to mashup retail shopping, auctions, analytics, reviews and coupons? For the VC-funded startup Mpire, you get a very useful set of shopping tools, what they call a universal shopping experience. They've used APIs from providers like Amazon, Shopping.com, eBay, Yahoo! Shopping and others, taken that data and analyzed about 10 trillion transactions, then provide shoppers not just the usual comparison search but also tools like historical price trends so you can see them over time. Somewhat akin to what Farecast does for travel. Here's an example of price trend analysis for iPods:
And while there has been this Mpire listing in our mashup directory for awhile, this week they launched Mpire Labs, a sandbox for trying-out new ideas in API-driven shopping. The first example is their Shopwave application that lets you visually compare products.