What is ‘SAL for SA’ and how can I use it for my SharePoint hosted customers?

‘SAL for SA’ are SKUs available in SPLA to reduce the license costs for those customers which are outsourcing their IT-infrastructure and already have a volume license agreement with Software Assurance (SA). The SALs for SA offering in SPLA allows the service provider to provide a multi-tenant application offering to their customers while they can take advantage of a price point based on their existing Software Assurance status.