The term "double duty dollar" was used in the US from the early 1900s through the early 1960s, to express the notion that dollars spent with businesses hiring African Americans -- ‘‘simultaneously purchased a commodity and advanced the race’’. Where that concept applied, retailers who excluded African Americans as employees effectively excluded them as patrons too.
Religious leaders as well as social activists such as Booker T. Washington and Marcus Garvey urged their communities to redirect their dollars from suppliers who excluded African Americans to suppliers with more inclusive practices.  Though the Swadeshi movement had much broader goals, Mohandas Gandhi also famously urged his countrymen, in the 1920s, to avoid funding their own subjugation by buying things from the British -- things they could produce and trade independently, like cloth and clothing. In the 1940s and 50s, Leon Sullivan applied the broader phrase selective patronage to note consumers' choice of suppliers as a tool a) to influence suppliers toward fairer, more just interactions with African Americans, and b) to build demand for African American suppliers.
While African American efforts continue, the strategy has also been applied by others for different, but similar reasons: to create economic incentives for gay-friendly suppliers; to decrease food miles; to decrease the environmental impact of agriculture and make it more sustainable; to make local economies deeper, etc. The double duty dollar concept can now be seen as part of a broad spectrum of consumer activism or ethical consumerism strategies.