This document discusses when to use SharePoint, Yammer, or a custom solution for social and collaboration needs. It provides details on the features of SharePoint and Yammer and when each product may be suitable. A custom solution is recommended when integration with other systems is required, customization beyond out-of-the-box features is needed, or legacy systems must be supported. The document analyzes the strengths and limitations of each option to help determine the best fit based on an organization's requirements and preferences around data hosting, mobility, user experience and control.