To an outsider the whole Heathrow issue seems to be problem solving along the lines 'If you build it they will come'.
In passing, according to Heathrow Funding Limited definitions: 16/10/2013
Transfer” traffic relates to passengers who use an airport for the sole purpose of connecting from one aircraft to another. They are counted as both arriving and departing passengers. “
Transit” or “In-transit” traffic refers to passengers who arrive and depart on the same aircraft within 24 hours. “
Point-to-point” or “origin and destination” traffic refers to any traffic that is not transfer or transit traffic and originates from or terminates at a particular airport.