The cooperativity index in a metallopolymer can be thought of as an estimation of the level of available water in nature. In a river, the water molecules can only feed immediate surroundings. Those in an aqueduct possess sufficient potential energy to extend this beneficial effect to wider areas. Twenty centuries ago, the Romans exploited this concept for extending their settlement in Western Europe. A reliable access to allosteric cooperativity indexes might push host–guest chemistry toward unexplored areas. More information can be found in the Full Paper by C. Piguet et al. on page 8113 ff.