How the scam works:

The incredibly fit 50 year old at your gym spends half his workout talking about the fantastic properties of açai berry juice. You're interested, and you know you've seen ads for it before, but you can't think of when.

Then one day, you're cruising the social networking sites and you see it - açai juice! And you're in luck - this ad comes as a promotion! First bottle free. Lose weight, feel healthier - "I'd be a sucker not to do it," you think.

You sign up for the promotion and type in your credit card information. A month later you get the juice. You try it out, it's fine. You get on with your life. A couple months later, you notice a hefty charge on your credit card. $100 for a "subscription fee" for a free bottle of juice.

You try to get a hold of them; they don't take your calls. And then as you're re-reading the fine print, you notice that it does mention the charges. That makes it even harder to cancel. You end up spending four times as much money compared to just buying from a legitimate seller.

Other variations of the scam: Sometimes the product will be diluted with cheap juices. Other times, it will come as a liquid pill soaked in preservatives. FYI, the best way to maintain the antioxidant properties is to freeze it.

How to avoid:

There are numerous health food stores in any city. Go into one and buy it, rather than ordering from a shady business on the internet. It may be a little more expensive but at least you know what you're getting.

Make your friends and family aware of this scam by sharing it, using the buttons provided.