You have just answered your own question.The only thing that really matters to clubs, in terms of membership, is revenue.
Membership numbers are just a gimmick, mainly to attract sponsors. Not sure why so much importance, among the general public, placed on membership numbers.
I would prefer to see membership revenue figures. Anyone know when and where these are available for the whole league, or is it an individual club thing.
High membership numbers produce more sponsorship $$$.
So, revenue from memberships is not the only thing that really matters, as more members (database for sponsors) = more overall revenue for the club, regardless of the costs of that membership.