The ELIPSS Panel (Étude longitudinale par internet pour les sciences sociales), largely inspired by the LISS Panel of the CentERdata, aims at providing social scientists in France with a survey infrastructure that allows the administration of web questionnaires to a probability-based sample. The monthly questionnaires fielded in the panel are designed by academic teams and should not exceed 30 minutes. The pilot study of this online panel started in 2012 with the offline recruitment of a sample of 1000 individuals representative of the French-speaking population living permanently in France and between ages 18 and 75 years. The first survey was carried out in April 2013. When conducting surveys of the general population over the web, one issue is to deal with the inclusion of individuals who have no personal access to the Internet. To address this issue, each ELIPSS panel member receives a 7-inch touch screen tablet and a 3G subscription in exchange for his participation. Equipping the entire panel with the same device presents several advantages. For instance, ELIPSS questionnaires are administered through a specific application which ensures that all respondents answer identically designed-questions. Indeed, it avoids one problem of web surveys related to the multiplicity of browsers and screen sizes used by respondents. However, other challenges have to be overcome when conducting Internet surveys of the general public with mobile devices. This paper will focus on the main issues raised by using tablets in a longitudinal study and as a new mode of data collection in social science research. The representativeness of the panel will be the main question addressed, particularly in respect to age and ease with new technologies. The incentive effect of giving a tablet and internet access will also be approached from the angle of panel attrition and panel conditioning. In particular, we will examine the effects on response behaviours of the panel members and the effects on their usage of new technologies over time. Finally, we will discuss opportunities offered by ELIPSS to the researchers designing questionnaires, and will present some examples of surveys using specific features of the tablet to collect data.