This paper is discussing the general applicability and usability of new forms of tourism as an option for development and poverty reduction. Five common new forms of tourism are critically analysed: Ecotourism, Community based tourism, Fair trade and ethical tourism, Pro-poor tourism, and Sustainable tourism. In order to reflect on the complexity of the chosen subject, this paper distinguishes relevant approaches to development, sustainability and tourism by identifying seven principles of sustainability in tourism. While it is a challenge in itself to measure and analyse these, this paper attempts to clarify to which extent the new forms of tourism live up to sustainability standards in the Stay another day initiative in Cambodia. 58 projects have been evaluated that define themselves all in combination of development and sustainability standards. The analysis revealed that not only Sustainable tourism, but also Community-based tourism, both lost their original meaning due to an inflationary usage of the concepts. Moreover, sustainability principles in tourism are applied according to the tourism actors’ suitability, and can not live up to the holistic demand of the sustainable development approach. As the main focus of the initiative is on the travellers’ experience, a relevant debate on authenticity enriches the discussion. Furthermore, this paper reveals that alternative forms of tourism need a certain amount of cooperation or partnership to be successful. Hence, when tourism is used as a means of supporting the locals in development processes and poverty reduction, it is in need of the cooperation of its actors. Thus, the tourism industry, governments, Civil Society, as well as travellers themselves are asked to work together in order to minimize the negative impacts of tourism on the host destination.