Before revision:  In this paper we study the problem of estimating the relative value of  spatio-temporal data sold in wholesale and retail data marketplaces for the purpose of forecasting future demand in a certain area, e. g. a city.
After revision:  In this paper we study the problem of estimating the relative value of spatio-temporal datasets combined in wholesale and retail data marketplaces for the purpose of forecasting future demand in a certain area, e. g. a city.