Culture is any set of shared customs and ideologies in a particular society group or place. The importance in writing across media is that culture will determine which medium a message should be conveyed in, which messages will be more effective in a particular culture or sub culture, and which concepts can be utilized to get the desired message across in the most impactful way. Culture is the foundation of all communications, the more shared ideas and beliefs and customs that are touched upon, the stronger the message.
Cultural Model of Communication Edit
"The cultural model of communication sees communication as the construction of s shared space or map of meaning within which people coexist" Communication of ideas is the entire point of writing across media, this theory states that a common culture must be established in order to have effective communication and existence.
 Grossberg, Lawrence, and Ellen Wartella. MediaMaking: Mass Media in a Popular Culture. Second ed. Thousand Oaks, Calif.: Sage Publications, 2006. Print.