Online travel agencies (OTAs) play an important role in the online travel market. OTAs offer various features, rich information, and numerous hotel choices for customers. All these hotel choices, accompanied by detailed information and supported by various website features, are generally beneficial and advantageous for hotel customers. They allow hotel customers to evaluate numerous hotels based on different characteristics, including price, location, amenities, and ratings. However, the reasons why OTA users postpone their booking decisions and switch to other hotel booking channels remain unclear. Therefore, this dissertation aimed to explore the determinants of OTA users' intention to postpone their hotel booking decisions and their intention to switch to other hotel booking channels by developing and testing a conceptual framework based on the integration of stressor-strain-outcome (SSO) framework and information processing theory (IPT). A sequential exploratory mixed-methods approach, comprising two phases (i.e., qualitative and quantitative) was employed as the research design for this dissertation. In the first phase, themes that hold significance in influencing OTA users' intention to postpone their hotel booking decisions and intention to switch to other hotel booking channels were explored by conducting thematic analysis on qualitative data collected from OTA users through three online focus groups. In the second phase, the themes that emerged from the qualitative data analysis were utilized to formulate a quantitative survey instrument for a more in-depth investigation of the research problem. A total of 700 online surveys were collected, and structural equation modeling (SEM) was conducted to analyze the quantitative data and test the study hypotheses. The study results revealed that information overload, choice overload, and system feature overload, as stressors, positively influenced strain factors including similarity confusion, ambiguity confusion, time risk, psychological risk, performance risk, privacy risk, emotional exhaustion, decision task difficulty, and untrustworthiness toward OTAs. The results also indicated that similarity confusion, performance risk, emotional exhaustion, decision task difficulty, and untrustworthiness toward OTA, as strain factors, had a positive impact on OTA users' intention to postpone their hotel booking decisions. The results further indicated that ambiguity confusion, time risk, performance risk, decision task difficulty, as strain factors, had a positive impact on OTA users' intention to switch to other hotel booking channels. This dissertation provides valuable theoretical contributions to the existing body of knowledge in the realms of travel, tourism and hospitality industries and offers significant practical implications for OTA operators to generate effective and efficient strategies to be more competitive in the travel market and avoid unwanted consequences.