Software vendors, service providers, and cloud vendors need each other to survive. Application development and delivery (AD&D) leaders need them to work well together to succeed. But how these complex relationships work is a mystery. Forrester drew on hundreds of client inquiries and interviews with 17 software vendors and service providers to find out what’s really going on. We found an alliance landscape that’s opaque and rapidly shifting as software as a service (SaaS) becomes the norm. This report sheds light on how service partner programs work and outlines best practices for how AD&D leaders should work together with their service providers and software vendors.