Swami Vivekananda's quote:
Karma Yoga is a method of purifying the mind through work. ... All fear and all desire to enjoy here or hereafter must be banished for ever by the Karma Yogi. The karma without desire of return will destroy selfishness, which is the root of all bondage. The watchword of the Karma Yogi is "not I, but Thou," and no amount of self-sacrifice is too much for such a person.

This quote of Swami Vivekananda leads to many questions to introspect how this approach can benefit in a capitalistic society. Please read a dialog with Swami Tyagananda of the Ramakrishna Vedanta Society of Boston.
A Dialog on Karma Yoga