True, but they have only ever done it for one off games and I am not sure those figures would ring true for the course of a few games or over a season. Other factors to take into account that dont stack up for one off games are things like merch, where someone going to a one off game isnt going to buy a top, someone going every week would. Also there is no momentum, if a kid is going for free every week there is a good chance that that spreads throughout their friend groups etc where as if they need to pay they may only go once in a while or not at all depending on their family's financial situation or other commitments/ cheaper alternatives.
and then of course if you hook them young, they become paying ticket holders down the line.