I never tried it but I have read it is all about getting in great shape at home which is what tons of people seem to be doing since they don't have the time or money to join a gym.
Unlike lots of other programs they seem to get that weight loss is not what people are looking for when they want results but rather how they look at the end of the program. They seem to have countless (and legit) before and after pictures.
Their program is probably geared to replacing fat with muscle to look great. I think their program is heavily based around circuit training with body weight exercises, but am not positive.