This document discusses building companies on the cloud. It provides definitions of cloud computing and discusses some of the benefits it provides for startups, including lower infrastructure costs without large capital expenditures, the ability to scale up and down more easily based on demand, and a more level playing field compared to traditional IT. However, it also notes some concerns about security and loss of control. It argues that for small and medium businesses, data may be safer and more secure in the cloud if the cloud provider is chosen carefully. It sees public clouds, private clouds, and a combination of both as having long term viability depending on the situation.