In order to accurately and reliably quantitate HLE on the plasma membranes of the lymphocytes and mononuclear phagocytes, a test sample containing the lymphocytes and mononuclear phagocytes is initially treated with a first antiserum specific for CD4 receptors on the plasma membrane or with a second antiserum specific for chemokine receptors on the plasma membrane. In one embodiment, a method includes performing a regression that estimates elasticity of demand for a retail item, wherein the regression is performed on a transformation of a demand model that does not include variables associated with base demand or seasonality. An association of a detected launching of the first object with user input effecting that launching, if any, is stored.