We're used to seeing start-ups built on top of APIs. We even wrote a series of posts to do it yourself. Fueled by the popularity of location-sharing site FourSquare, marketers are using the FourSquare API (our FourSquare API profile) to promote their products.
For months, the Bing Maps site has been showing off what are essentially embedded mashups. You can search nearby tweets, FourSquare check-ins and other content from partners. Until now, it was merely a showcase of apps either written internally or by a company that Microsoft had blessed. Now, you have the opportunity to get your mashup included on Bing's map.