Mobilizing Group Membership: The Impact of Personalization and Social Pressure Emails in the United States
- Enrollment and attendance
- Community participation
- Nudges and reminders
- Recruitment and hiring
Emails have the power to reach a large number of individuals at a low cost and with ease, and thus offer great potential as a tactic for group mobilization. This study evaluated the efficacy of three different types of emails in encouraging group membership: an impersonal email, a personalized email, and a personalized email that included an element of social pressure. Researchers found that membership increased most among recipients of the social pressure email followed by recipients of the personalized email.
Policy issue
Mobilizing group membership and action is an important challenge for many organizations, from political campaigns to professional associations. Email messages reach a large number of individuals with ease at a low cost, and may therefore represent an effective tool for mobilization. However, there can be drawbacks to email mobilization as well. Recipients may view impersonal emails with apathy or even irritation. Indeed, past studies have found email mobilization to have no effect on voter registration among college students.1 Theory suggests that personalizing the correspondence may increase its effect on behavior, particularly when the recipient knows the sender. Beyond personalization, social pressure may also increase the behavioral impact of messages. A previous experiment found that exerting social pressure by informing citizens of their own and their neighbors' voting records increased voter turnout more than simply informing citizens that their own voting records were being observed.2 This study is the first randomized experiment to evaluate the impact of personalized and social pressure messages sent by email.
Context of the evaluation
The researchers conducted this study during the recruitment drive for a large, professional organization that has over 15,000 members and 36 subsections. Members of the organization must file a petition with at least 200 signatures in order to form a new subsection. In order to remain active, a section must maintain at least 250 dues-paying members. The section that the researchers focused on was recognized in 2010 and had 214 members in 2011 at the time of the recruitment drive. As co-presidents of the subsection, the researchers wanted to boost membership and sent recruitment emails to 280 individuals who had signed the initial petition for the creation of the section, but failed to pay the small additional fee necessary to formally join the section.
Details of the intervention
The researchers used three different types of emails in order to evaluate the effect of personalization and social pressure on group mobilization. The 280 individuals who received recruitment emails to join the subsection of the professional group were randomly assigned to receive one of three emails: 93 received an impersonal email, 93 received a personalized email, and 94 received a personalized email that included an element of social pressure. The impersonal email opened with "Dear Colleague" and continued with a generic message encouraging the recipient to join the new subsection. The personalized email included a brief personalized note before the "Dear Colleague" message and addressed the recipient by name. Finally, the social pressure email included the same brief personalized note, addressed the recipient by name, and also alluded to the fact that the recipient had signed the petition in support of the section previously, but not yet joined. The researchers sent emails from February 23, 2011 to March 22, 2011 and checked the group membership list on March 25, 2011. Researchers sent a second round of emails to the 86 individuals who initially received the impersonal email but failed to join, randomly assigning individuals to receive either the personalized or the social pressure message. This took place from May 9, 2011 to May 17, 2011 and the membership list was checked on May 31, 2011.
Results and policy lessons
The study found that group membership increased most among recipients of the social pressure email message, second among recipients of the personalized email, and least among recipients of the impersonal email. Only 5 percent of individuals who received the impersonal email joined the section, while 20 percent of individuals who received the personalized email joined the section, and about 30 percent of individuals who received the social pressure email joined. During the second round of emails, 16 percent of individuals who received the impersonal email followed by the personalized email joined and 42 percent of individuals who received the impersonal email followed by the social pressure email joined. This suggests that the influence of social pressure is strong and may be enhanced by multiple email messages. The fact that email recipients had previously expressed support for joining the section may explain the relatively large effects researchers observed. More generally, these results provide evidence that using social pressure and personalization in email messages can be effective means of organization-building and recruitment.