More marketing research is being conducted using online surveys. Response rate is an issue because of the importance of these data for business decision-making. This study uses a sample of 1,501 from an existing opt-in online survey research panel to gain insight into the motivations to participate in online research, and to identify the right participation incentives. The findings suggest that respondents are motivated by their perceived level of expertise to offer relevant information, familiarity with and trust toward the sponsors of the survey, the propensity for sharing and participation in social media, sponsors' valuing their opinions through feedback, and sponsors' addressing privacy concerns appropriately. Further, the study segments responses by their type and frequency of social media use. Those with high participation and high information needs are motivated by all of the factors identified. In contrast, those who mostly socialize on social media are motivated by familiarity with sponsors, the opportunity to share online, and having privacy expectations met. Those who use social media mostly to seek information are motivated to participate by trust in sponsor, and having privacy expectations met. The types of incentives that work best to increase participation are consistent with the motivations identified: information about the nature and enforcement of privacy protection policies; ability to earn points toward rewards for quality of online contributions; and enforcing an online code of conduct. These results are of interest to marketing researchers because they identify strategies for improving participation that are within managerial control and are not dependent on intrinsic characteristics of the participant.