Clarifying for alisonkisk, lend means 20 cards instead of 10 you need for heating, lending the other 10 out to a neighbor for his heating. Economies of scale,

Clarifying for alisonkisk, lend means 20 cards instead of 10 you need for heating, lending the other 10 out to a neighbor for his heating. Economies of scale, for instance by buying more cards at a time at a better unit price.