Willy Loman's primary motivation is to become a successful salesman and attain the American Dream by becoming financially secure. Unfortunately, Willy Loman fails to realize that being well-liked and popular does not translate into success. Although Willy enjoys working with his hands and being outdoors, he sacrifices his true desires in an attempt to attain the American Dream. During Willy's funeral, Charlie mentions that Willy had all the wrong dreams and his pursuit of the American Dream was futile. Willy’s motivation to become wealthy also contributes to his mental instability. As a failed salesman, Willy begins to hallucinate and becomes completely delusional. One could argue that his motivation to be a success contributes to his mental instability.
In addition to sacrificing his desires and engaging in an unfulfilling job, Willy's motivation to attain the American Dream also ruins his relationship with his son, Biff. Instead of cherishing Biff's personal attributes and encouraging him to find a job he desires, Willy holds his son to unreasonable expectations and is upset that he has not attained financial success. Willy believes that Biff has purposely failed to become a success out of spite and will never be satisfied until Biff becomes a wealthy, established businessman. Overall, Willy's motivation to attain the American Dream results in an unfulfilling life and ruins his relationship with Biff. If Willy had not placed such importance on becoming a financial success, he could have found joy as a construction worker and possibly had a better relationship with Biff.
The play emphasizes the last period of Willy Loman's life but also reaches back into his past to help the audience understand how he reaches his fateful decision. The two main motivations in Willy's life were closely intertwined. He wanted to be a good salesman and also a good family man. Sadly, he had to accept that he had not truly succeeded at either one.
A deep, unfulfilled need for acceptance drove Willy's dream of excelling in sales. To him, the sales were a verification of other people's endorsement of his character—being liked. That insecurity essentially disabled his chances of success; he had an unfillable emotional void.
In contrast, he assumed that love, support, and acceptance were his due within his family. While he is motivated to be a good provider, he is unkind to his wife and expects his sons to rise to meet his expectations rather than nurturing the relationships.
Finally, however, Willy abandons the goal of sales success. His motivation changes to providing for Linda as she ages so she can stay in their home. Wanting security for her, he chooses to end his life for the insurance, not understanding that she would rather have her husband alive.
Willy Loman is a typical high-strung salesman, always looking for the bottom line, and always trying to get ahead despite his lack of ability. While he is generally competent, he tends to dream higher than his actual abilities, and so he strives for an excellence he does not possess instead of being satisfied with mediocre successes. His motivations are to become independently wealthy like his brother, and to be admired by the other salesmen and public figures he sees in his daily life. The play shows that he could have been happy with his life, if he had not been driven to different ideals; his family comments that he seemed to truly enjoy building, rather than selling:
CHARLEY: Yeah. He was a happy man with a batch of cement.
LINDA: He was so wonderful with his hands.
BIFF: He had the wrong dreams. All, all, wrong.
(Miller, Death of a Salesman, kevindeweese.com)
In this sense, his motivations changed him from a realistic man to an idealistic, almost mystical man. He didn't believe in his ability to be successful based on his own merits, but he did believe that he could somehow stumble on luck if he just worked hard enough. Had he been more grounded in reality, he could have become a contractor or even just a laborer, but he thought that the difficult life of selling would be enough to achieve his ideal of greatness.