In a capitalistic economy, the MCM model seems to work sell for creating and maintain wealth. (MCM’) would mean the buyer (or capitalist) purchases a product with the intention to re-sell and turn a profit, therefor create wealth. M’ at the end of the MCM’ formula means the money at the end of the transaction would be greater than the beginning amount. Once again referring to a capitalistic business transaction, the buyer will purchase a commodity at a lower value and plan to resell that same product for a higher value. Thus creating more profit and opportunities to build capital.
Businesses may purchase commodities or assets (loyal, skilled workers). Those commodities then become capital to further business profits by utilizing their value by reselling them (commodities) or selling their skills, respectfully. Also, with employing people, business must provide way for laborers to support their labor power. The laborer (or working-class person) sells their product or skills to obtain money (wage) which is used to tend to their personal needs, therefor reinforcing their labor power.
But how do businesses stay afloat if they have to pay their workers? That’s where surpluses labor comes in. Surplus labor is the money made after the worker has recouped what the company has paid them for a work day. If a cashier is paid $12/hour and within 4 hours of their shift they rang up $500 in sales, well the company has made $404 plus whatever the cashier will ring up during the last 4 hours of their shift. The company will only pay the wage agreed on between them and the worker. Therefore the company is getting free (surplus) labor with 100% profits.