The advent of Social Networking Systems (SNS) has introduced new possibilities for planners to refine and extend conventional engagement and data-gathering techniques by leveraging user-contributed, spatially-referenced content freely available online. This study examines the use of SNS content as community input, complementing input gathered through traditional participatory processes such as workshops, public comment hearings, and charrettes. Four case studies of recent community planning projects in the United States are analyzed, comparing the data gathered from traditional participatory processes with available SNS content related to each project study area, to determine to what extent the inclusion of SNS data would improve the overall data- gathering efforts of these projects. Three significant findings emerge from this analysis: (i) that SNS data analysis can positively complement data gathered from traditional participatory processes, (ii) that although SNS data analysis can provide useful data to planners, it is not a direct replacement for conventional engagement techniques, and (iii) that SNS data analysis is most effective for projects in neighborhoods with a well- defined identity. The study also examines the characteristics of effective SNS data analysis integration and discusses broader implications for planning practitioners and additional research needed.