Exploitation enters the picture only with the use of the extracted and capitalized surplus. If the surplus is used for essentially private consumption and transaction costs of capitalists - it is exploitation. However, if it is used for general benefit of society as a whole (investment in public goods, etc.) - it is a mechanism of social progress.
Wojtek
^^^^ CB: Yes, the more the socially produced is socially appropriated and less privately appropriated, the more today's society moves into the realm of freedom.