One reason many marketers don't even think about this is that they don't even know there's an option to expand their view of the customer journey. They've never had access to data outside of their own brand's perspective through Google or their marketing automation data.
But, with access to new technologies available today, more and more companies are tapping into the entire consumer journey. Third party intent data is opening up a whole new world to marketers today, providing a sharp competitive edge. By not leveraging this available data, companies risk losing out on business.