Sentence:  In America alone, people spent $170 billion on “direct marketing”—junk mail of both the physical and electronic varieties—last year. Yet of those who received unsolicited adverts through the post, only 3% bought anything as a result. If the <WSD>bumf</WSD> arrived electronically, the take-up rate was 0.1%. And for online adverts the “conversion” into sales was a minuscule 0.01%. 
Meaning of the word marked with <WSD> tags:  Useless papers; now especially official documents, standardized forms, sales and marketing print material, etc.