When shopping by mail, you're always taking a risk. When the offer sounds too good to be true, it probably is. What you'll get is information about how to rip someone else off the way they just cheated you. Federal law only protects you if you sign the contract in your home or somewhere other than the normal place of business. Health spa memberships.
Most complaints center on high-pressure sales tactics.
People often buy timesharing vacations on impulse. Be sure you're ready to go to the same place during the same period of time for years to come.