SAS 70 is a set of guidelines for evaluating service organizations, providing comprehensive assessments of their control objectives and activities through independent audits. Type I reports evaluate the description of controls, while Type II includes testing results over time, benefiting both service and user organizations. SoftLayer underwent SAS 70 certification to demonstrate reliability and operational efficiency in its IT services, responding to industry demands for standardized audits and compliance with regulations like the Sarbanes-Oxley Act.