Wattal and colleagues study how using internal and external APIs changes the variety of products in the WordPress platform. By looking at plug-in data over ten years, they discover that APIs are organized into three layers: the complete core, the regular core, and the periphery. They find that external APIs in the regular core help create more product variety. However, this effect becomes weaker in new product categories. Their research shows that as digital ecosystems grow, they become more complex than the simple core-periphery models used before.
Software Components and Product Variety in a Platform Ecosystem: A Dynamic Network Analysis of WordPress
