'The First Million'
The 'A.P.' series were the most effective of leaflets used against Germany in WWI. (The meaning of 'A.P.' is still not yet clear. Suggestions such as 'Aerial Post', 'Aerial Propaganda', 'Air Post' and similar have been made). No complete official list of these leaflets nor the dates of dissemination are known despite the fact that about nine million leaflets of about ninety types were disseminated. They were all despatched by small free balloons and delivery depended on favourable winds. In some cases it appears that the wind was a most decisive factor so that leaflets were not necessarily dropped in numerical order. The earliest seems to have been March 1918 and the last just before the Armistice.
Another series Truppen-Nachrichtenblatt were disseminated in the closing months of the war and were printed about three times a week with a run of 100,000 copies. They were termed 'priority' leaflets as they gave up-to-the-minute news and were despatched by balloon to German troops promptly as against the 'stock' 'A.P.' leaflets which could be allowed delay before ballooning. Lists of both series are given in Blatter No.10, published by the Psywar Society.