1. A method comprising: receiving, at a search engine provider and from a user device, an initial query submitted by a current user; identifying additional queries relating to the initial query; identifying one or more respective advertisements for each of the additional queries from an inventory of advertisements; determining a respective measure of commerciality for each additional query based at least in part on a graph having: nodes corresponding to queries users have previously entered in search sessions and edges connecting the nodes, and an edge connecting, from among the nodes, a first node and a second node representing that the users have previously entered a second query represented by the second node after entering the initial query represented by the first node, wherein a weight of the edge represents a likelihood that the second query will be entered by the current user following the user's entry of the initial query, and wherein the commerciality for each additional query represents an estimated amount of revenue the search engine provider will receive by providing one or more of the advertisements identified for the additional queries in response to entry of the additional query by the user; selecting the second query based on the second query having a highest measure of commerciality among the additional queries; and updating a user interface of the user device to incorporate a presentation of the second query with content blocks that include one or more of the advertisements identified for the second query and search results associated with the initial query.