Many of the online websites that are hawking the acai berry and the total cleanse are set up to offer a free trial that actually signs people up for a continuing draw from your credit card.
So those particular websites are scams. The acai berry itself has many proponents, not necessarily for weight loss purposes, but for health benefits. If you do buy it, make sure to get it from a reputable vitamin company because it is very unstable in pill form (it loses potency very quickly). There are many reputable vitamin companies that have cleansing products.
So if you want to try the products, you can do it a lot less expensively if you go to the health food store and buy the products.
Hope this is helpful,
Rasby