9. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: receiving, by a client device and from a search engine, a first search results page including a first set of search results; after receiving the first search results page by the client device and before receiving an indication of a request from a user to display a second set of search results, providing, by the client device, the first search results page for display; after providing the first search results page for display, requesting, by the client device, a second search results page including the second set of search results; after requesting the second search results page including the second set of search results, receiving, by the client device, the second search results page; pre-caching the received second search results page on the client device; and after receiving the indication of the request, from the user, to display the second set of search results: obtaining the pre-cached second search results page; providing the obtained pre-cached second search result page for display; and before receiving an indication of a request, from the user, to display a third set of search results, and in response to providing the obtained pre-cached second search result page for display, transmitting, by the client device, a confirmation, to the search engine, that the obtained pre-cached second search results page was displayed.
9. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: receiving, by a client device and from a search engine, a first search results page including a first set of search results; after receiving the first search results page by the client device and before receiving an indication of a request from a user to display a second set of search results, providing, by the client device, the first search results page for display; after providing the first search results page for display, requesting, by the client device, a second search results page including the second set of search results; after requesting the second search results page including the second set of search results, receiving, by the client device, the second search results page; pre-caching the received second search results page on the client device; and after receiving the indication of the request, from the user, to display the second set of search results: obtaining the pre-cached second search results page; providing the obtained pre-cached second search result page for display; and before receiving an indication of a request, from the user, to display a third set of search results, and in response to providing the obtained pre-cached second search result page for display, transmitting, by the client device, a confirmation, to the search engine, that the obtained pre-cached second search results page was displayed. 16. The system of claim 9 , wherein the second search results page includes one or more advertisements and the confirmation confirms that the one or more advertisements were displayed to the user.