Cause everyone needs to know when their coffee mug is on or off, there is now a visual indicating On-Off Mug that reads "off" without liquid and "on" when filled with a warm bevy. A special heat-sensitive pigment will turn the mug from black to white as the temperature increases, so you not only get your morning cuppa joe, but you get a magic show as well. Each mug is dishwasher safe and costs $25. What do you think? Love or leave?