Hitler was a charismatic leader - growing demand for authoritarian leadership and Hitler was the most charismatic leader. He continually offered the same promises - he would tackle Versailles, democracy, Marxism and create a Volksgemeinschaft. A new party member wrote: "The personality of the Fuhrer had me totally in its spell." This was a typical response.
Fear of Communism - many unemployed and marginalised turned to Communism, which scared the middle class into Hitler's arms.
Appealed to the marginalised - As unemployment peaked, many of the unemployed turned to Nazism so that one third of its voters were working class. Nazis won over many first time voters, who were facing mass unemployment. There were nearly 2m new voters and turnout increased noticeably.
Gained respectability - Harzburg front. Influence of sympathising elites like Goering, Schacht and Keppler encouraged support. Hitler's speech to industrialists in Duesseldorf i n 1932 also helped.
Better Party structure - developed under Strasser. Gauleiter and Fuehrerprinzip. Able to appeal to more people in wider areas.
Propaganda - 6000 trained public speakers passed through training school by 1933. They combined dramatic techniques like marches and loudspeakers. Adapted to local circumstances, focused in key districts, used grassroots feedback. Posters and leaflets which understood psychology. Tailored to the economic and social interests of specific social groups. E.g. offered benefits to farmers to offset prices, offered the unemployed bread and work, appealed to the Mittelstand, saying Nazism would limit department stores. Mass suggestion, converting people through the atmosphere of emotional mass rallies. Uniforms and music etc.
Unity - Volksgemeinschaft. Unity behind the Fuehrer. Scapegoating.