For me it sorta does not matter. When I boycott usually the thing disgusts me and any revenue less for them and more for their competitors especially in regards to how I act (consume) is important to me. Because its my actions. Like there is a lot of indication that the plastic recycling I do likely does not get recycled, but im still going to stubbornly do it. If I was in europe I would totally do the buy european. Will it change what trump is doing, unlikely, but it will help europe gdp over us.