CTR Prediction for Contextual Advertising: Learning-to-Rank Approach Yukihiro Tagami Shingo Ono Koji Yamamoto Yahoo Japan Corporation Yahoo Japan Corporation Yahoo Japan Corporation Tokyo, Japan Tokyo, Japan Tokyo, Japan
[email protected] [email protected] koyamamo@yahoo- corp.jp Koji Tsukamoto Akira Tajima Yahoo Japan Corporation Yahoo Japan Corporation Tokyo, Japan Tokyo, Japan
[email protected] [email protected] ABSTRACT if a user clicks their advertisements and visits the adver- Contextual advertising is a textual advertising displayed tiser’s site. To maximize revenue by choosing some ads from within the content of a generic web page. Predicting the candidates and ranking them to display, an advertising sys- probability that users will click on ads plays a crucial role in tem needs to predict the expected revenue for each ad. The contextual advertising because it influences ranking, filter- expected revenue from displaying each ad is a function of ing, placement, and pricing of ads. In this paper, we intro- both bid price and click-through rate (CTR). Bid price is duce a click-through rate prediction algorithm based on the the cost that the advertiser agrees to pay per click, so the learning-to-rank approach. Focusing on the fact that some advertising system already knows this. On the other hand, of the past click data are noisy and ads are ranked as lists, CTR for each ad can vary significantly in accordance with we build a ranking model by using partial click logs and then many factors such as the web page and user, so the system a regression model on it.