Research on oral nicotine pouches (ONPs) is relatively minimal compared to other nicotine and tobacco products due to the products' novelty. This dissertation characterizes the use of ONPs within a large, nationally representative adult sample, and examines the sociodemographic (e.g., sex, age group, race/ethnicity) and behavioral factors (e.g., current use of conventional tobacco cigarettes or CTCs) associated with ONP use (Study One), examines the association between exposure to ONP marketing (i.e., receiving discounts/coupons, seeing social media content) and ONP use (Study Two), and assesses the potential for smoking or vaping cessation using ONPs (Study Three). All three studies analyzed Wave 7 data from the Population Assessment of Tobacco and Health (PATH) Study, which is the first wave to include ONP-related questions with data collection occurring from January 2022 to April 2023. Specifically, the adult survey (i.e., those aged 18 and older) was used for all three studies. Analyses included chi-square tests and multivariate logistic regressions to examine the associations. Study One found males, those younger than 65 years old, Non-Hispanic Whites, those with a higher education, those with a higher household income, those having important people close to them that use ONPs, current use of CTCs, current use of electronic nicotine delivery systems or ENDS, and current use of other smokeless tobacco products or SLTs had higher odds of being aware of and using ONPs. Study Two found that those exposed to ONP marketing (i.e., receiving discounts and coupons for ONPs and seeing social media content about ONPs) exhibited higher odds of ever and current use of ONPs. Study Three found that ONP users were more likely to report intention to quit CTCs and ENDS for good, and consider switching from CTCs or ENDS to ONPs. However, the lack of a significant association between ONP use and being a current vs. former use of CTCs or ENDS indicates that ONPs may not be an effective method of smoking or vaping cessation. Given that ONP use has not been widely reported, this dissertation is a critical step in reporting ONP use as well as its associations with sociodemographic characteristics and use of other tobacco products. Specifically, identifying population groups at risk for ONP uptake can help better target public health campaigns towards preventing and/or intervening in ONP use. Stricter regulatory policies for ONP marketing may be necessary to prevent ONP uptake in such vulnerable groups at risk of ONP use. Similarly, regulations may be warranted to ensure that tobacco and nicotine companies are not falsely advertising ONPs as smoking or vaping cessation aids.