Personalizing banner ads or embedding ads with specific data signals or triggers, such as – personal characteristics, past behaviours, etc. is believed to improve customer response or Click Through Rate (CTR) since, embedding ads with viewers/recipients’ personal data or characteristics make ads more appealing and relevant to users (Lambrecht & Tucker, 2013). However, evidence also exists in literature that personalization can be ineffective as the usage of customers’ personal data can trigger off privacy concerns causing them to ignore such ads (van Doorn & Hoekstra, 2013). Investigations exploring suitability and effectiveness of ad personalization report that factors such as advertised product, data used for personalizing may influence the effectiveness of personalized ads (De Keyzer, Dens, & De Pelsmacker, 2015; Goldfarb & Tucker, 2011; van Doorn & Hoekstra, 2013). In this research we examine the impact of personalization triggers (PTs) on click through rate (CTR) of online banner ads across cultures. CTR data for 1345 unique ad copies (personalized) of an international hotel group screened in Japan and Middle East countries was used for this study. Data analyses revealed significant impact of PTs on CTRs. Analyses further revealed that – 1) usage of past purchase data impacts the CTR negatively, implying that customers respond negatively to ads showing hotel properties that they have previously visited/stayed in; 2) usage of search history data has a significant positive impact on CTR, suggesting that customers respond favourably towards ads showing hotel properties in destinations revealed from their search history. Interestingly, culture specific data such as local language elicit different responses in different cultures. While in Japan, language personalised ads i.e., ads in Japanese language fared poorly (negative impact on CTR) as compared to ads in English language (positive impact on CTR); in the Middle East it was the ads in English language that fared poorly (negative impact on CTR) compared to ads in Arabic. These results strongly suggest that the knowledge of PTs influence CTR and combining them with the right creative elements would help advertisers in improving customer engagement with ads, have a positive impact on CTR and even improve customer conversion. This would imply better returns for the resources spent on digital advertising. Findings from the study are true and reflective of the PTs (membership, brand affinity, destination, language) used in the ad campaign under study and limited to the cultures investigated. Future studies exploring other PTs in online hotel ads would help marketers in making a more informed decision while selecting data signals or PTs for personalizing digital banner ads for hotel brands.