Having gone for the quick fix in the past, I can understand the mentality as to why people choose this as an option. When you have a lot of weight to lose then following a normal diet with weightloss estimated to be around 1-2 lbs a week it can be soul destroying and a seemingly endless quest.
However, what I will say is that it doesn't change the mindset of why you're overweight, which means that the dieter will become a yo yo dieter.