They aren't necessary but they are convenient. Being able to adjust the temperature in the middle of the night is great but being able to to adjust the temperat

They aren't necessary but they are convenient. Being able to adjust the temperature in the middle of the night is great but being able to to adjust the temperature when on vacation is awesome. It's also flexible (will automatically adjust down if people are unexpectedly away for the day) and allows you to track energy usage more easily. Does everyone need one? No. But for some people the convenience is worth the money.