Function and income of the capitalist

Thus, capitalists advance present goods to owners of factors in return for future goods; then, later, they sell the goods which have matured to become present or less distantly future goods in ex­change for present goods (money). They have advanced present goods to owners of factors and, in return, wait while these factors, which are future goods, are transformed into goods that are more nearly present than before. The capitalists’ function is thus a time function, and their income is precisely an income represent­ing the agio of present as compared to future goods. This interest income, then, is not derived from the concrete, heterogeneous capital goods, but from the generalized investment of time. It comes from a willingness to sacrifice present goods for the pur­chase of future goods (the factor services). As a result of the pur­chases, the owners of factors obtain their money in the present for a product that matures only in the future.

... says Rothbard in Man, Economy and State (chapter 6). This truth has been bent and manipulated by many. The socialist propaganda says that the capitalist is exploiting the worker, because the capitalist "only" pays his workers e.g. 95% of the sales revenue and pockets 5% himself. The fact, however, is that the capitalist is paying the worker from his own savings, so that the worker can carry out consumption immediately after work, while the capitalist has to wait until the product is sold at a later time. The "fee" for this waiting is the income of the capitalist.