My thoughts on achieving the latter is to expose as many people to the services and at each point offer them a reason to join. In the case of a bottle shop, offer great prices to everyone to increase exposure but at every turn a nagging discount that quickly makes it worthwhile.
But what are the measures of success?
Well we can talk about return on investment, but as a not for profit we really only need to cover the reorder cost of the wine. Maximising profit is actually contra to the core mission of the Mess Committee.
Mess Membership is a poor indicator as there are close to infinite influences.
So then what?
Well the irrational part of me suggests that as good a measurement as any is for it to stock particularly great wines, namely:
Penfolds Bin 407
Samuel's Gorge Grenache
St Hallett Old Block
But, even more importantly, to discover new great wines, but that is another tale...
What would your measures of success be? What would your wines of choice be?