Methods and systems provide tracking or logging requests to resolve non-existent domain (NXDomains) and organizing the NXDomains to support searching of the domain names including ranking the NXDomains based on popularity, e.g, number of hits or potential traffic based on the number of requests made for the NXDomain. NXDomain logs may be organized so that it supports searching by creating an inverted index including n-grams of the NXDomains. Searching includes identifying a target substring in one or more of the indexes, selecting those matching NXDomains satisfying some threshold criteria, and displaying the NXDomains in a selected order such as by demand or popularity associated with, for example, a selected geographical location from which resolution requests targeting respective NXDomains originate.