El Segundo-based PK4 Media, which develops adveriting technology, said this morning that it has acquired Santa Monica-based Prosperio, a developer of a programmatic direct platform for the display and video ad market. Financial terms of the merger were not disclosed. PK4 Media said it has acquired Prosperio's programmatic direct platform, and will make that platform available later this year. PK4 Media said that the platform will provide a self-service solution for help marketers plan and run digital advertising campaigns. Prosperio was part of LaunchpadLA.