Good Posters!
Allied propaganda was far more effective than German.
The German government did not see the value of it and for the most part discounted the opinion(s) of the rest of the world.
As the war progressed, they did see keeping the US out of the war was in their best interest and they modified some of their U-boat operations accordingly.
Later in the war, they ramped up some internal propaganda, but that was more to bolster their own war weary population suffering from material deprivation and shortages owing to blockade and a war that seemed interminable.
"Ich kampfe fur Gott, Kaiser, und vaterland"
Richard