1. A computer-implemented method comprising: obtaining aggregate search data based on session logs of search queries submitted by users to a search engine during a predetermined time period of network search activity; obtaining a first list of search terms corresponding to a plurality of search entities; determining a search frequency for each search entity in the aggregate search data based on a corresponding search term in the first list of search terms; calculating search probabilities for each search entity based on the determined search frequency of the search entity in the aggregate search data, the search probabilities indicating a likelihood of search queries related to the search entity co-occurring with search queries related to one or more different search entities; estimating a level of search interest for each of the plurality of search entities based on the search probabilities; generating a search market model for the plurality of search entities based on the estimated level of search interest of each search entity during the predetermined time period; and providing an interactive visualization showing interrelations between the plurality of search entities of the generated search market model.