One of the most persuasive ways to influence someone to give is through his or her social networks. There is ample research showing that giving is a social act, and when someone we know asks us to donate, that has a strong effect.So what does that truth mean on social media? An optimist would say the bigger the social network, the more we get social sharing — and the better for our cause. But not so fast.A new study sent via my colleague Caryn says people with more Facebook friends are less likely to share information about charitable causes. The study says the reason may be that social butterflies believe someone else will do the work of playing champion: According to Futurity:“Economist Kimberley Scharf, from the Centre for Competitive Advantage in the Global Economy (CAGE) at the University of Warwick, claims when we have larger online social networks we rely on other people to pass on information about opportunities to give. This phenomenon is called ‘free riding.’”So what does this mean? Just because someone seems to have a big online following doesn’t mean they are your best messenger. What matters most is the commitment to the cause – not the sheer numbers of friends. When you are identifying the supporters who have the best shot at advancing your cause, focus on the level of commitment more than the level of fame.