What does the smart meter do better than you meter you have now?

Why do we need to get the smart meter if our meter is still working?|||The meter is now based on the distance that light travels in 1/c seconds, as opposed to the original meter that was based on the the length of a pendulum whose half-period was one second. Of course, c is derived from measuring how many meters light travels in one second, so the definition is a bit circular.