Research has shown that the non-internet population is hesitant to respond to online survey requests. However, also subgroups in the internet population with low digital affinity may hesitate to respond to online surveys. This latter issue has not yet received much attention by scholars, despite its potentially detrimental effects on the external validity of online survey data. In this paper, we explore the extent to which a person’s digital affinity contributes to nonresponse bias in the German Internet Panel (GIP), a probability-based online panel of the general population. With a multi-dimensional classification of digital affinity, we predict response to the first online panel wave and participation across panel waves. We find that persons that belong to different classes of digital affinity have systematically different socio-demographic characteristics and show different voting behavior. In addition, we find that initial response propensities vary by classes of digital affinity, as do attrition patterns over time. Our results demonstrate the importance of digital affinity for the reduction of nonresponse bias during fieldwork