I've had Good Sam for years and never needed them until my Suburban broke down towing my car trailer about 150 miles from home. They would only tow the truck to the nearest dealer (who couldn't get parts for at least two weeks) and wouldn't tow the trailer at all, except to move it to a safe place (out of the road). I ended up putting the Suburban on the car trailer and paying a friend to tow me home. I wasn't very impressed with Good Sam at all. And that was with the Platinum Plan, or whatever their top of the line plan is called.
And yes, I got a ton of junk mail and emails trying to sell me more of their services.