Sentence:  First there was Mr. Newmarket, symbol of the new male customers for prophylactics sent to you by doctors as a result of Schmid's "Exclusive Trichomonal Re-infection Control Program" —the program that created a whole new <WSD>marketful</WSD> of prophylactics users. 
Meaning of the word marked with <WSD> tags:  A sufficient number of potentially interested consumers.