Got this via SMS from Globe Telecom (PH): "Make sure that there are no running applications connecting to the internet when using the service to avoid incurring data charges"

Tried it in the Philippines and it works well. One possible problem here is that for smartphones, users may be charged unexpectedly because background apps that access the net. There should be a separate APN for Free Zone use so users are sure they are not charged for normal data rates. I don't think users will use this if they are uncertain that it is totally free.