potential to reduce energy consumption, to avoid accidents, to cut driving costs, and to optimize parking utilization. As a result, they could provide lower-cost services to public transport users and, eventually, replace an important part of private cars. However, several researchers and analysts are sceptical about AVs capacity to gain user's acceptance in the midterm, and then to achieve profitability for providers. The present study explores factors of a successful implementation and diffusion of taxi services based on AVs (known as robotaxis). From users' perspective, our study is based on Stated-Preferences Surveys. We interviewed more than 500 of persons commuting in Palaiseau, a city located on the south of Paris. Results stated that robotaxis will likely be used for short-distance (2 to 5 km) commuting trips by two user profiles: (1) non-motorized young users (less than 30 years old) and (2) motorized active population between 30 and 50 years old. The evaluation of users' preferences regarding fares, waiting times, travel times and transfer times is performed considering all existing modes. It suggests that the trip fare should be less than 6 euros and the waiting and travel times from 4 to 8 minutes. From operators' perspective, key performance indicators (KPI) are defined to assess technical and economic performances in different contexts: urban vs. rural area, last-mile vs. doorto-door service, taxi vs. fixed schedule, and so on. KPI values are indicated based on existing literature. Finally, the analysis is extended to predict the most likely evolution of AVs penetration and diffusion.