In just the first four days since her tragic death, disco queen Donna Summer's album sales have surged more than 3,000 percent, including a 10,000% increase in sales of her former No. 1 album, "On the Radio: Greatest Hits," which has sold 6,000 copies in the last four days to come in at No. 73 on the Billboard 200 albums chart.  Sales of all Summer's albums went from just 1,000 the week before her death to 26,000 in the four days since she died.