"W.R. Williams (1867-1954), better known as sheet music and vaudeville sketch publisher Will Rossiter, composed vaudeville and patriotic songs between 1894 and 1926. In the Rotarian magazine article I found, they credit Williams with inventing the practice of 'plugging', or using stage performance as a way to promote/sell sheet music."

from

http://blog.dinosaurdiscs.com/