As much as we all hate to admit it, advertising has a hold on us. I don’t even like cars, but when I see a slick Mercedes (PINX: DAI) commercial, I’m tempted. “If I have to drive to work, shouldn’t I do it in style?” Worse is tech advertising. The Apple Keynote (NYSE: AAPL) speeches make me want to rob my own mother's purse and go buy all the iPads. And I’m a normally sane person. So clearly ads can make us act in a way we normally wouldn’t, but can they be used on the supposedly smartest people in the world to boost the economy? That’s a question people are asking as we head into the G-20 Summit. Many countries are struggling, yet billboards are going up talking about how everything is going to be okay as long as we keep investing. Thinking about how the whole system of money is essentially a story we all tell ourselves, then I guess this is a possibility. We can print money, so why can’t we will economic prosperity into existence? Japan’s tottering economy is especially hopeful that the ads will help, as they have a lot riding on the outcome.