A randomized experiment was conducted to assess the effectiveness of three forms of e-mail appeals to prospective members of a newly formed professional group.The baseline condition consisted of an impersonal appeal; prospective members were sent a mass e-mail encouraging them to join.Participants in the personal condition received an e-mail with the same content, prefaced by First Aid Kits a personal note from the group president.Participants in the social pressure condition received a personal note that called attention to the fact that they had previously signed a petition to form the professional group and urged them to make good on their earlier pledge (i.
e., signing of the petition).Personalization is found to generate strong and statistically significant treatment effects.Even Basketball - Socks stronger are the effects of social pressure.