Specifically w.r.t to advertising: In socialist contries there is often only one single brand of a certain product. This removes the need for advertising. But without competition, productivity goes south with time.
But they were unable to generalize this.
After the Soviet Union collapsed, various companies sprang up to sell Soviet goods. I bought a marvelous small telescope, an old-fashioned electro-mechanical telephone, and a mechanical submarine clock. (Note that these were all obsolete technology.) They were all made by former military suppliers.