The document describes a study on typo-squatting domains and their impact on traffic to target domains. The study involved collecting DNS traces to identify typo-squatting domains, building a classifier to detect parked domains, and measuring traffic to typo domains and its effect on target domains. The results found a small percentage of traffic went to typo domains, with most users correcting typos, suggesting typo-squatting has a negligible impact on target domain traffic.