Viral altruism? A natural field experiment of social contagion in on-line networks

We present preliminary results from a small-scale natural field experiment aimed at exploring online social contagion, with an application to charitable giving. We worked in partnership with Heifer International, a non-profit organization aimed at fighting poverty in developing countries, and HelpAttack!, the developer of a Facebook application that facilitates donations to charities while broadcasting such activities to the donors’ Facebook contacts. We ran a series of marketing campaigns, and randomized the broadcasting of users’ pledges, thereby creating exogenous variation in the information that users’ contacts were receiving. Although our campaigns reached as many as about 13 million Facebook users, 6,000 users clicked on the ad and only 18 pledges were made, without any subsequent pledge from these users’ contacts. We offer potential explanations for this finding on the absence of network effects, and outline our plans for future developments of this on-going project.