"For fact-checks to be effective, they must first and foremost reach their intended audience. Yet, little is known about what determines engagement with fact-checks and how to enhance their reach. We conducted a pre-registered online survey experiment in Pakistan (N participants = 302, N observations = 1208) investigating the effectiveness of fact-checking, and the determinants of engagement with factchecks and misinformation. We found that fact-checking reduced misperceptions, especially among the most misinformed. Trust was an important moderator of the effectiveness of fact-checking and of engagement with both the fact-checks and misinformation. For instance, fact-checks were more effective among participants who trust the news the most and least effective among participants who trust social media the most. Participants more concerned about misinformation were more likely to like and share fact-checks on social media. Understanding and promoting engagement with factual corrections on social media is a pressing challenge to increase the quality of our information ecosystem." (Abstract)