Most People will embark on a Fitness Quest to Lose Weight and Tone up. This can get confusing if they rely on the scale to help chart their progress (considering their two goals; 'weight' loss and toning at the same time).
Keep in mind that 'Fat' Loss can be different from 'Weight' Loss. Reason is, with weight loss, you'll definitely see it on the scale, but fat loss means losing JUST Fat (which is what most people really want).
While Toning up, your fat will decrease but your muscles will Increase, and thus renders the scale an unsuitable equipment to rely on for charting your progress, simply because it may show you no/or very little weight loss (which can be very disappointing and misleading for many).
Still, this also depends on your fat percentage to begin with. A person who is Obese (25 and over in Fat Percentage for men, 35 and over for women), will indeed be able to use the scale to see a great difference in weight. But for those (under 25%; men, under 35%; women) who are just trying to shred off that little pudge, using a Tape Measure instead will better help to show the improvements in Bodyshaping.