“…Less expensive than paper-and-pencil surveys (Barry 2001, Eaton et al 2002, Duffy 2000b, Frankel et al 1999, Granello et al 2003, Lakeman 1997, Lenert et al 2002, Matz 1999, Rhodes et al 2003, Roos 2003, Stewart 2003 Increased pool of study participants (improved external reliability, generalisability) Matthews 1999, Meyerson 2003, Pittenger 2003, Rhodes et al 2003 Increased access for sensitive issues, cultural groups and 'hidden' populations (Adler and Zarchin 2002, Barry 2001, Birnbaum 2004, Bowker et al 2004, Duncan et al 2003, Duffy 2000b, Eaton et al 2002, Fyfe et al 2001, Im et al 2003…”