We repeatedly hear that software-as-a-service (SaaS) vendors are too numerous (and too small) for formal sourcing processes to apply in all cases. At the same time, the business-led, ungoverned model of "shadow" SaaS deployment has proven problematic — for cost, technology architecture, and security. SaaS app stores promise a way to alleviate this burden and help AD&D pros be more successful with sourcing and governing the proliferating landscape of SaaS vendors. This report discusses the landscape of SaaS app stores and the pros and cons of the different models.