The volume includes an introduction and an overview of the field and makes the case that employee affinity groups are a burgeoning phenomenon with great philanthropic potential. Since 2000, the number of affinity groups has grown sharply and now includes Asian American, Latino, LGBT, and Native American groups. They are seen as having the potential to simultaneously meet corporate and employee objectives. These employee networks point to a potential sizable, pooled and emergent source of philanthropic capital. This volume was produced through the Donor Research Project which was an initiative of the Center on Philanthropy and Civil Society.