There are a number of ways to discuss API popularity. Our metrics are based on developer engagement. The "track" functionality on ProgrammableWeb lets developers declare an interest in receiving updates on particular APIs. Which APIs and categories are seeing the most activity.
Visible Measures, a content advertising technology company, today announced the launch of the True Reach API, hoping to provide its advertising and technology partners access to Visible Measures’ database of five trillion data points on video content across more than 4,000 brands.