One example of zero state response being used is in integrator and differentiator circuits. The order of the integrator and differentiator add increased flexibility to the controller. Efficient distribution of its product has always been a main competitive differentiator for Wilsonart. The social networking component of Boxee is the differentiator from other media center software. Capacitive reactance is the important factor in the analysis of the operation of a differentiator. Scale is one key differentiator between different forms of programmable matter. In the 2010s, software has become a key business differentiator. One main differentiator of the product is the ability to load custom visualizations. Among those attributes, luster is the most important differentiator of pearl quality according to jewelers. A true differentiator cannot be physically realized, because it has infinite gain at infinite frequency. The key differentiator in status and economic position was between urban and rural dwellers. A main differentiator of pregnancy behaviors is socioeconomic status. A second effective differentiator is to examine the identities that guide human behavior. The operator p in the Heaviside calculus initially is to represent the time differentiator . For him, the most relevant differentiator was the bigger brain.