Because people absolutely refuse to do the things that will actually result in weight loss, (diet & exercise) there are a flood of gimmicks being sold that claim to do it for you, with no sacrifice. I understand that someone is now selling shoes that are supposed to cause weight loss.
Sensa is a combination of chemicals (silica, maltodextrin, tricalcium phosphate and others) that allegedly cause a sensory hypnosis that convinces your body that it's no longer hungry. Even if it does this, there is no guarantee that, once you stop paying $60 a month for Sensa, the same problems won't return. This is the downside of most fad diets; they are usually quick-fixes.