Here's an example: A German company pays to advertise to a German consumer. It used to be that the money spent on that advertisement went to a German advertisement company, so that money would stay in the German economy, and the system would be sustainable, with money flowing around the system but not escaping. Now the ad money ends up in the Cayman Islands via Ireland and none of it is retained in Germany because the multinational advertising company has no/very few employees in Germany (no salaries/income tax) there's no VAT (because the ad sale is a B2B transaction) and there's no corporate taxes (because the ad company uses transfer pricing - e.g. licensing of IP that they can price arbitrarily - to shift all their profits to Ireland where they make them disappear in a puff of smoke). The end result is that money is being siphoned out of the German economy and into tax havens (so there's no return flow like there'd be if this was just normal trade with other active economies) making it harder and harder to sustain the German economy. There's a leak in the system when selling to consumers, and if it's left unchecked it'll slowly collapse the middle class and consumerism as we know it. I'm not sure if revenue tax is the best solution, but we need A solution. (or you know, we could just blame the foreigners and let the weakest parts of society fight over the jobs and shreds of wellfare state that are left, which seems to be the preferred solution these days). Mind you I'm not arguing against international trade (which increases competition and drives down prices) but against the unfair competitive advantage that multinational companies, especially digital ones, have over local companies by not needing to pay taxes at all. We need an even playing field, tax-wise, that's all.