the previous poster had it right: it's definitely up the person to make the program work.
I lost 35lbs this year due to exercise & changing up what I ate. When I hit a plateau in June, I turned to weight watchers to give me more accountability for what i was eating (ie. group meetings, weekly weigh-ins, etc). If you
had to do a program, I believe weight watchers would be the cheapest one at $14/week (depends where you live though & they do have the occassional specials).
If you are serious about losing weight, it's common sense: take in less calories & excercise. Use a food journal to keep you honest; that makes a world of difference
sorry if i sounded like a know-it-all