Can someone summarize how they manage to do this? I once read that it involved t...

		sown on Nov 20, 2012 \| parent \| context \| favorite \| on: World's tallest skyscraper to be built in just 90 ... Can someone summarize how they manage to do this? I once read that it involved that they sell a product rather than a service. I don't know where I read that but I'm curious why this doesn't apply more often to other products?