As an emerging technology, Generative Artificial Intelligence (GAI) is assumed to be one of the most effective technologies across various levels of management. Yet, current studies have yet to investigate the factors that affect the adoption of generative AI tools among employees in the workplace and its impact on the organization's economic sustainability. This study aims to contribute to our understanding of GAI adoption and usage factors in organizations and their impact on economic sustainability in the context of Non-Profit Organizations (NPOs). It extends the UTAUT theory with AI attributes and privacy risk factors. A quantitative methodology was followed, and the survey was used as an instrument. Random Sampling technique was followed and data from 302 employees were collected from NPO organizations and analyzed, leading to valuable insights and implications. The results show that most of the factors significantly affect GAI adoption, such as Facilitating Conditions, Performance Expectancy, Privacy risks, Social Influence, Perceived Anthropomorphism, and Perceived Animacy. Surprisingly, two factors were not significant: effort expectancy and perceived intelligence. Also, the effect of using GAI on economic sustainability is significant. The model explained GAI adoption with 62.7% predicting power. These results shed light on the importance of encouraging employees to use GAI in the workplace while ensuring that robust data protection measures are covered to waive employee concerns.