Modeling Attractiveness and Multiple Clicks in Sponsored Search Results
This work addresses the problem of accurately modeling user clicks for sponsored search results, which is crucial for search engines to optimize ad placement and revenue, though it appears incremental by building on prior click models.
The authors tackled the limitations of existing click models in sponsored search by proposing a new model that shares information across results and accounts for non-sequential user interactions, achieving improved performance as validated through experiments on commercial search engine logs.
Click models are an important tool for leveraging user feedback, and are used by commercial search engines for surfacing relevant search results. However, existing click models are lacking in two aspects. First, they do not share information across search results when computing attractiveness. Second, they assume that users interact with the search results sequentially. Based on our analysis of the click logs of a commercial search engine, we observe that the sequential scan assumption does not always hold, especially for sponsored search results. To overcome the above two limitations, we propose a new click model. Our key insight is that sharing information across search results helps in identifying important words or key-phrases which can then be used to accurately compute attractiveness of a search result. Furthermore, we argue that the click probability of a position as well as its attractiveness changes during a user session and depends on the user's past click experience. Our model seamlessly incorporates the effect of externalities (quality of other search results displayed in response to a user query), user fatigue, as well as pre and post-click relevance of a sponsored search result. We propose an efficient one-pass inference scheme and empirically evaluate the performance of our model via extensive experiments using the click logs of a large commercial search engine.