I do it to keep on track. Also, to see what is working for me, like others have said. Alternately, anytime I have had any weight gain, I also wasn’t checking in on my weight regularly. I had previously gone from 266-218 on another diet plan, this is when I started to add daily weigh in, though I only use my Wednesday weight as the “official” number. I was able to maintain for a few years within 5-10 pounds. Eventually I crept up over 230 and I knew it was time to get back in track. I also don’t use the scale as my only metric for success. The way my clothes fit, measurements, energy levels, bloating, etc, are all ways I measure my success. The scale just gives you a number and it doesn’t tel the whole story. It can’t account for muscle mass (unless you have a pretty fancy one) constipation, water retention around my period, or if a stall is actually a stall. So take everything into account. It’s taken me years and I still have days where I see the number on the scale and that’s all I can focus on. I need the reminder of how far I’ve come and I get that from my amazing network, but also of pictures of myself.