In the present paper, 4 experiments are outlined that examine context effects in signing up to a panel, and subsequent maintenance of membership and completion of surveys. In Study 1, N=10,000 Open University students were invited to join a panel by the vice-chancellor of the University. They were addressed as either 'Dear Forename', 'Dear Forename Surname', 'Dear Student' or 'Dear Open University Student' (each n=2500). Significantly more people joined the panel if addressed as 'Dear Forename' compared to 'Dear Student' or 'Dear Open University Student'. In Study 2, the salutation effect was tested on a second panel using an invitation to leave the panel (sent by the vice-chancellor). In this case, significantly more people left the panel when addressed as 'Dear Student' than 'Dear Forename', signalling that the salutation effect is not merely a superficial response, but is due to a deeper psychological process such as identification with the organization or strategic behaviour. In Study 3, panel members (n=1405) were asked by a neutral power person to participate in a survey, with a diffusion of responsibility (group size) manipulation. No effect of salutation or group size on response rates was found (mean response rate: 82%). However, there was a significant interaction between the salutation used when invited to join the panel (Study 1) and that used on the first invitation, on response rates and motivation measures. In Study 4, salutation and power were manipulated within the same experiment. A strong salutation effect was found when power of the sender was high, and not when power of the sender was neutral. Conforming with the social identity model of de- individuation (SIDE) it is argued that for this sample, responsibility and identifiability linked to create a strategic imperative to join and maintain membership of an online panel. Future studies will examine the impact of power and status of the sender, strategic behaviour and socially desirable responding in online surveys.