What are the four fundamental ways in which a business can grow its revenues and profits?

The four fundamental ways in which a business can grow its revenues and profits are 1) Sell more unites, to existing patients 2) sell to new units by attracting new patients. the more patients you see the more revenues are brought in. 2) Sell the same unites at higher cost 3) sell the same units however produce them at lower cost, example is finding products that provides the same quality care at a lower cost, in order to lower the cost of sale.