One of the most important features of as CRM platform is the ability to modify, extend, and integrate the application. When choosing a cloud platform, this Computer World article suggests that you carefully evaluate it for CRM applications to ensure the CRM is likely to be robust and durable.
"Is the platform well thought-out and coherent way to integrate, or is it a bunch of marketing hooey? I spent too many years of my life marketing baloney to developers: Don't get taken. There's two reasons for a cloud platform: ease of development and reach/scope of integration with other applications. Look at the APIs for consistency and scope. Can you get at all the important objects in the CRM system? Are the APIs strewn across 17 dlls, or are they a logical set of Web services? Are all APIs available from any subsystem, or is the platform partitioned? Can an application start a CRM transaction or workflow from outside the platform, and can an outside system fully participate in the CRM application's triggers and workflows?"