After the advent of the digital platform, any medias can't be separated in any terms of advertising and marketing activities.
Imagine if you spend the budget to traditional TVCM, it increasingly interact other medias such as Google, Twitter, Facebook,YouTube and so on. They are not isolated but interact each other.
Marketers have been tried to integrate individual marketing activities in their campaign but it still have been in trial process. The buzz word, "Big Data", might enable marketers/data scientists grab the social interaction by multiple medias usage. But consumers already do.
The medias are consolidated by consumers even if the one is a traditional and no-digital stuff.
It's necessary to understand media environment before paying attention to the purchase process.
I believe that sociological insight would be helpful for marketers to plan their marketing activities in the era of totaly-mingled media situation.