Selecting advertisements for placement on related web pages

A processor-based system for selecting advertisements for placement on a series of web search results pages, the system comprising:

• a first ranking module executable by a processor and configured to rank a plurality of advertisements to generate a ranked plurality of advertisements by using a first model to determine a probability of each advertisement being selected by a user when that advertisement is shown to the user on a first web search results page in the series of web search results pages;
• an advertisement placement module executable by the processor and configured to select one or more highest ranked advertisements from the ranked plurality of advertisements for placement on the first web search results page;
• a second ranking module executable by the processor and configured to rank remaining advertisements of the plurality of advertisements that were not selected for placement on the first web search results page to generate a ranked plurality of remaining advertisements by using a second model to determine a probability of each remaining advertisement being selected by the user when that remaining advertisement is shown to the user on a second web search results page in the series of web search results pages, the probability associated with each remaining advertisement being determined based at least in part on one or more user selection feedback features associated therewith, the second ranking module comprising:
• a user selection feedback feature generator executable by the processor and configured to obtain the one or more user selection feedback features associated with each remaining advertisement by comparing one or more attributes associated with each remaining advertisement to one or more attributes associated with one or more user-selectable items on the first web search results page that were not selected by the user;
• the advertisement placement module being further configured to select one or more highest ranked advertisements from the ranked plurality of remaining advertisements for placement on the second web search results page.

A computer-implemented method for selecting advertisements for placement on a web search results page that follows one or more initial web search results pages in a series of web search results pages generated in response to a user query, the method executable by a processor of a computing system and comprising:

• obtaining, using the processor, features associated with each of a plurality of advertisements that were not selected for placement on an initial web search results page, the features including user selection feedback features determined by comparing one or more attributes associated with each advertisement in the plurality of advertisements to one or more attributes associated with one or more user-selectable items on the initial web search results page that were selected by a user and one or more user-selectable items on the initial web search results page that were not selected by the user;
• determining, using the processor, a user selection probability associated with each of the plurality of advertisements based on the obtained features associated therewith;
• ranking, using the processor, the plurality of advertisements based on the user selection probabilities;
• and
• selecting, using the processor, one or more of the plurality of advertisements for placement on the web search results page other than the initial web search result page based on the ranking.