Kevin Kern described Konica/Minolta's use of commercials, newspapers, social media, and other media to control the marketing message. Which marketing concept was he referring to?

Answer: Marketing mix

Explanation: Marketing mix refers to the group of marketing tools that the firms use to implement their marketing strategy effectively in the target market.

In the given case, Konica/Minolta's are using various sources of media such as commercials, newspapers etc. to spread their marketing message. Thus, they are using these tools for their promotional purposes.

Hence from the above we can conclude that the concept they are referring to is marketing mix.