San Antonio's chain

When I was in the elementary school (which was long time ago) I happened to know what was going under the name of "San Antonio's chain".
It worked this way: you wrote five post cards to five people and any one of them had to write five post cards and so on.
I do not remember how it really worked, because I guess I never played, but somehow and someway you got a certain amount of post cards and so on.
"Do not stop the chain...unless this or that".
Many years later I saw it was very successful in USA, with the most unusual things at the place of post cards.
And I see it still works pretty well.
You always find the sufficient number of people happy to go on and fearful to break the chain.
I guess the home business was something like this.
You bought a house and you made a loan, you sold it and bought a bigger one making a bigger loan and so on...
The problem was, somebody, somehow broke the chain and the full business showed its real face.
But I agree, America will recover, because of the never ending ingenious of some people on one side and never ending naiveté of others on the other side.
Next time it will not be houses, it will be something else, but who cares?
The important is that nobody breaks the chain...