Progressive User Adoption
http://www.uxmatters.com/mt/archives/2009/03/progressive-user-adoption.php

Hughes, Michael A.
UXmatters
2009

Abstract:

User assistance can add value to a product or Web service’s business model by influencing how deeply users adopt new features or services. As more products employ pay-as-you-go models like that of SaaS (Software as a Service), the contribution user assistance makes becomes increasingly more important.