The term "Holocaust" didn't exist in the German language until the 1980s. Due to the great success of this mini-series, it became common knowledge, and was chosen as "word of the year 1979" by the "Gesellschaft für deutsche Sprache" (Society for German Language).
When this was aired on German television, it included the "Krystallnacht" scene, where people were smashing the windows of synagogues and Jewish-owned businesses. When that segment was shown, police station switchboards were flooded with confessional calls from people who had participated in the actual event, calling to confess their participation. The Statute of Limitations had run, however, and no action could be taken despite their confessions. Subsequently, the West German Government altered the relevant laws to extend the time limits, to enable the prosecution of such perpetrators.
Meryl Streep only took this role for the money, which went towards her then boyfriend John Cazale's cancer treatment.
When broadcast in West Germany, it was shown simultaneously on all the regional broadcasting stations of ARD, the so called "Third Programs". It was watched by more than twenty million people and resulted in broad public discussion about genocide.
So many people watched this mini-series in New York City when first broadcast, that when commercials were on, the local water pressure dropped, due to so many people using their toilets at once.