This contribution presents four business challenges associated with a potential secondary use of European TV white spaces by LTE networks. Based on a quantitative study for 11 representative European countries, we show that Europe's TV white spaces are relatively scarce, diminishing, spatially scattered and heterogeneous, as well as rural in nature. These intrinsic characteristics of the spectrum have implications for the exploitation scenarios by secondary LTE networks that regularly appear as promising use cases. We discuss these implications relation to three LTE use case scenarios: femtocell deployments, rural coverage deployments, and LTE broadcasting/ multicasting deployments