In Death of a Salesman, who is Dave Singleman and what impression did he have on Willy Loman?

As he grovels in the office of a distracted and
disinterested Howard Wagner, pleading for an in-town job, lowering his salary requests
again and again, Willy Loman desperately relates a histrionic story of the
eighty-four-year-old Dave Singleman who, without ever leaving his hotel room, conducted
a successful sales career. When he died the noble "death of salesman", hundreds of his
associates - out of love and respect - attended his funeral. In fact it was the manner
of Singleman's death, not his life, which drew Willy to embrace salesmanship and to turn
away from the pioneering, 'Horatio Alger' type of career offered by his brother, Ben. In
this decision, Willy rebuffs the rugged individualism and the indifference to social
relationships exemplified in Ben Loman. Rather, Willy chooses Singleman's way, a life of
loyalty and friendship, a life cocooned in a web of sustaining social relationships. But
when Willy's manner of death is juxtaposed with Singleman's, its irony and tragedy are
all the more poignant, for Willy dies alone.