Every interaction you have with another person either gains or loses you social capital with that person.
For example, driving someone to the airport gains social capital. Having that person ride the bus while you drive to the same location costs you social capital.
Social capital can be converted into favors, appreciation, assistance, loans, love, and even real cash.
Work hard to earn social capital and spend it wisely for social capital is perhaps even more effective than monetary capital.
How do you earn and spend your social capital?