Non-profit organizations, corporate volunteer programs, and government workplace schemes are asking volunteers for their time and effort. But, with the changes in how people volunteer, such as episodic, micro, and cyber volunteering, those managing volunteers need to understand whether they should focus on encouraging volunteers to donate more time or effort. Using public service motivation to measure volunteer’s propensity to engage in volunteering, we compare three outcomes: time spent volunteering, frequency of volunteering, and volunteering intensity. In a sample of 411 volunteers, we find public service motivation is associated with more time spent volunteering, increased frequency, and higher levels of volunteering intensity. However, volunteering intensity explains the most variance. These findings suggest that how the individual perceives they exert volunteering intensity may be useful among public service motivated volunteers.