Editing Porter's generic strategies (section)

===Variants on the differentiation strategy===
The '''shareholder value model''' holds that the timing of the use of specialized knowledge can create a differentiation advantage as long as the knowledge remains unique.<ref>William E. Fruhan, Jr., "The NPV Model of Strategy—The Shareholder Value Model", in Financial Strategy: Studies in the Creation, Transfer, and Destruction of Shareholder Value (Homewood, IL: Richard D. Irwin, 1979)</ref> This model suggests that customers buy products or services from an organization to have access to its unique knowledge. The advantage is static, rather than dynamic, because the purchase is a one-time event.

The '''unlimited resources model''' utilizes competitors by practicing a differentiation strategy. An organization with greater resources can manage risk and sustain profits more easily than one with fewer resources. This provides a short-term advantage only. If a firm lacks the capacity for continual innovation, it will not sustain its competitive position over time.