> I don't think advertising makes that much difference. Most people spend all their earnings. The only thing advertising does is direct where it is spent.

Even if it were true that advertising only directed where money was spent, there'd still be 2/3 less money to go to advertising or anything else if everyone was making 1/3 pay.

  > If we all did it then we wouldn't be working longer and harder for the same pay.  

I don't understand what you're trying to say. Economies of scale mean that you're more productive with more consumption. IE) If you write code for a living, you're generating more value the more people who use it. If less people use it, you have to work harder to get the same level of value and the same pay.