What are the biggest technical challenges you have faced in launching a WiFi network?

The technological challenges that we have faced in launching our WiFi networks are not mainly centered in the deployment of networks itself, but rather on the construction of the associated innovative, profitable and sustainable business model. Apart from the difficultness of defining the model, on the technological side both our Roaming system and our Geo-located advertising platforms had to be built using what in the time of developing were yet emerging technologies