In the previous section, you saw how a mashup profile lists the APIs that are used in the mashup. You can take a given API and find out all the mashups that use that API. For example, you start with a list of the most used APIs:
http://www.programmableweb.com/apis/directory/1?sort=mashups
Then you find the profile for the Google Maps API, the most popular of all APIs in ?ProgrammableWeb:
http://www.programmableweb.com/api/google-maps
From that link, you can click the Mashups link to arrive at the list of the 1,200+ mashups registered that use the Google Maps API: