On reflection, maybe I can answer my own question (but tell me if I'm wrong): The EU rules demands that, in the market for beer (or trains or spyware) sold in

On reflection, maybe I can answer my own question (but tell me if I'm wrong): The EU rules demands that, in the market for beer (or trains or spyware) sold in France, the French govt. cannot favor French companies over Irish companies. The buyer must be free to buy from any of them on equal terms. But it does not demand that the market for goods sold in Dublin is identical to the market for goods sold in Paris. Hence the VAT rates may differ, as may other more narrowly focused taxes, like on alcohol, or hotels. This tax is one more like that. A sin tax on spyware. Edit: There remains the issue of deciding where a sale took place. Alcohol to be drunk in Paris has to be physically in Paris (even if the sin tax is collected long before the final sale), but an advertisement shown in Paris could have been bought by a company elsewhere. Why can't every French ad agency open a one-man office in Dublin to avoid this?