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Personal means to be focused on the persons and not on what the business is doing. Business is about supply and demand. A service or product is in demand and a business supplies what is in demand. Personal is bad for business if it interferes with supplying the demand.

Is demand constant? Business is for-persons. Are they incentivised to supply or to be supplied?

I don't understand your reference.

How supply-demand are related? increase supply from zero to something, how it affects demand?