The treadmill is a wonderful invention, allowing us to control the impact, intensity and surfaces on which we're moving. The fact that treadmills usually give a visual readout of calories burned, pulse rate and other pertinent information makes it something of a motivational tool, too. Best of all, you can zone out while listening to music or podcasts.
Certainly, walking on a treadmill can be a great addition to your weight loss efforts. However, it's just one part of the puzzle.