This study examines, through a content analysis of the census of news stories posted in a Colombian online political community, how status cues and informational cascades shape participation in online political discussions. Specifically, it looks at how the authors’ news stories posting increase rate, the number of news story sources, the velocity at which comments to a news story start to appear, and the comment interactivity affect discussion participation. Results suggest that cues that signal expertise influence participation, while discussion among users also influences the decision of others to participate. However, the effect of these variables is stronger for some topics. Implications for the constitution of public spheres are discussed.