According to Porter, "The degree to which rivalry drives down an industry's profit potential depends, first, on the intensity with which companies compete and, second, on the basis on which they compete." He goes on to note that "Rivalry is especially destructive to profitability if it gravitates solely to price because price competition transfers profits directly from an industry to its customers." Briefly describe two of the four conditions that increase the liklihood of rivals competing on price (in one sentence or short bullet point each).