Methods and systems for analyzing network traffic related to domain names, including Non-Existent Domain names, comprise: storing network traffic data associated with DNS requests for NXDs; receiving an analysis request associated with a domain name; creating, based on the stored network traffic data, an NXD list comprising NXDs that received at least one DNS request during a specified time period; computing, based on the stored network traffic data, a similarity metric for each NXD listed in the NXD list; and providing an analysis report identifying potentially valuable NXDs based on the computed similarity metrics.