From a marketing standpoint, why did companies use racist caricatures like Mammy and Rastus (Aunt Jemima and Cream of Wheat) to sell their products? How would these characters convey quality? What message would the companies have been trying to capture?

Using those images and tropes evokes the fantasy version of the “old plantation south”, a heavily fictionalized version of the southern United States. This was purportedly a “simpler time” where Black people were happy to be enslaved and work tirelessly to feed and take care of their white masters.

From a marketing perspective, those images were designed to evoke feelings of comfort, childhood (the Black servant by taking care of the white children), (frankly) white supremacy, and having someone who would take care of you (or at least your breakfast in these cases).

They weren’t concerned about the images being racist. Many Black people complained about such imagery for decades; the solutions were always to simply have the characters no longer speak in ads (print, radio, or filmed). In the case of Aunt Jemima, they slimmed her down and gave her a curly wig to replace her traditional “mammy” headscarf.