When the charges for data usage rolls out on 1st March there are bound to be many members who get charged for data they did not realise was being used. This will result in many unhappy bunnies and probably mayhem on the forums and questions to agents.
About a week before live date advise members of their average usage in say January (or anything that will give someone a clue that they WILL be charged). I would think that some people might not realise that their favourite game connects to get adverts or something else needs data to operate. Have seen some incredible figures for data usage on the forums and it is surprising just how much data some apps use for no real result.
To save work this could be restricted to those who only use small amounts of data each month.