Increasingly tourists decide spontaneously how long their holiday should be and where to go. Official tourist statistics and market analyses, which are the basis for investment decisions, only cover longer periods and are published annually or even biannually. They are then used to develop long-term tourism strategies. The challenge for the tourism industry is to be able to react pro-actively against increasingly short-term tourist decisions. New methods are needed for optimized investment that responds to tourists’ more changeable travel, decision and consumption behaviour.