The new Odeon Premiére Reward Card: is it worth it?

The Odeon cinema chain has recently brought out its own reward card, but there's a catch: you have to pay for it. They've made it even more confusing by introducing three different levels of payment, each accompanied by a different number of 'free' rewards points.

The question is, is it worth forking out for a card? And if it is, which level do I go for?

I used the power of maths to work out an answer to both questions, and posted it at my regular blog, here.