Questionnaires were distributed as e-mail attachments to personal contacts, and to members of the public on the social networking sites Twitter and Facebook. Other respondents were collected by snowballing on the basis of the original contact group. Although access was a major driver in the sampling approach, this convenience sampling approach was also beneficial in building a sample in which respondents all had the shared characteristic ofusing a mobile phone (Riley, Wood, Clark, Wilkie, & Szivas, 2000).Hair, Bush, and Ortinau (2006) suggest that self-selected sampling is suitable for exploratory research when prior knowledge of the population’s characteristics is not sufficiently present.