Online search advertising (aka, sponsored or paid search advertising) is a technology that any matched advertisement is displayed on Web pages as online users’ query results from search engines and Web portals (e.g., Google, Bing, Baidu, Naver, and Yahoo!). In specific, after online users type search keywords on the search box (at this stage, online users become searchers), search engines match users’ query texts to phrases included in search advertisement. Then, if an advertiser’s investment on her/his search advertisement is high enough, the advertisement is likely to be displayed on a search engine results (called “impression”) (Hanson and Kalyanam 2007; Jansen et al. 2009; Jansen and Clark 2017; Moore, Stammerjohan, and Coulter 2005). Once a searcher clicks a displayed advertisement and arrives on the advertiser’s landing page, s/he becomes a visitor by clicking the impression. As benefits of utilizing search keywords, online search advertising can reduce search costs and increase information accessibility by potential customers. In addition, because online search advertising provides relevant search results based on the users’ own queries, it is considered less intrusive than banner advertisement and widely used by many marketers (Ghose and Yang 2009; Johnson, Bruner, and Kumar 2006; Quinton and Khan 2009; Rangaswamy, Giles, and Seres 2009; Yang and Ghose 2010).

• Moon Young Kang(Soongsil University, South Korea) | Moonyoung Kang
• Sunghoon Kim(Arizona State University, United States)