Chain letters and pyramid schemes are some of the oldest scams going around. They can cost a lot of people money, as they spread like a virus. People who become involved in these scams can only make money by scamming other people.
Pyramid schemes and chain letters are often promoted by people you know and trust, but who may not realise that they are taking part in an illegal scam.
These scams are often very easy to spot and avoid if you know what to look for.