1. One or more non-transitory computer-readable media storing instructions which, when processed by one or more processors, cause: an information service receiving, over one or more communications networks from a client device, one or more alphanumeric keywords, wherein both the one or more alphanumeric keywords and an information service indicator that uniquely identifies the information service are displayed to a user of the client device in visual content on a non-Web page medium; the information service identifying, at a first time, one or more first search-limiting criteria that both correspond to the one or more alphanumeric keywords and provide a first context for the one or more alphanumeric keywords, wherein the one or more first search-limiting criteria are not included in the visual content on the non-Web page medium; the information service providing both the one or more alphanumeric keywords and the one or more first search-limiting criteria to a search engine, wherein the search engine performs a first search using both the one or more alphanumeric keywords and the one or more first search-limiting criteria and generates first search results; the information service receiving the first search results from the search engine; the information service transmitting the first search results over the one or more communications networks to the client device; the information service identifying, at a second time that is different than the first time, one or more second search-limiting criteria that both correspond to the one or more alphanumeric keywords and provide, for the one or more alphanumeric keywords, a second context that is different than the first context; and the information service providing both the one or more alphanumeric keywords and the one or more second search-limiting criteria to the search engine, wherein the search engine performs a second search using both the one or more alphanumeric keywords and the one or more second search-limiting criteria and generates second search results.
3. The one or more non-transitory computer-readable media of claim 1 , wherein the one or more first search-limiting criteria include one or more additional alphanumeric keywords.