In reply to S Ramsay:
its just a pricing tactic, the centres tend to be £15/m before they open, then up to £20 after the opening and it then climbs steadily as the customer base matures to between £30-50/m
as for the subsidsing, yeh the current centers support the opening of more, i wouldn't call it subsidising though as these centres are designed from the ground for profitability first and climbing second. they also share holds and staff. OJ (picture 2 in the article) joined Hangar Plymouth and now sets at, at least, thier south west locations