The SSP design had a major flaw in that it was set up using a collection of services, and any web applications linked with the SSP had to bear the overhead of all of the services, even if they weren’t in use. A new SSP would have to be built to alter the service configuration for a specific web application.
The service application architecture, on the other hand, provides for the association of one set of services with one web application and another set of services with another web application. Furthermore, the same service application can be configured differently in different web applications; as a result, websites can be set up to use only the services that are required, rather than the full bank of services.