With the diffusion of digital technologies, organisations are exploring innovative business models based on inter-organisational data sharing collaborations. This study explores the key aspects that position data spaces a sustainable choice for inter-organizational data sharing compared to traditional data sharing ecosystems. The research is designed in two-phases. In the first phase, a comprehensive secondary analysis of data space initiatives, use cases, and authoritative sources (DSSC, GAIA_X, IDSA) is conducted to identify the core value propositions of Data Spaces. In the second phase, data spaces are compared with alternative data sharing ecosystems including data marketplaces, data commons, consortia etc, to evaluate the business models that data spaces enables and support. The findings will provide an actionable insights for both organisations and orchestrators to design innovative business models and incentive mechanisms to align multi-stakeholder business objectives for sustainable data sharing in data spaces.