Tracking consumer across devices

Consumer has different mindset when using different devices. PC, phone, tablet, TV, radio, etc.
Advertisement on TV and Facebook will have different perception on the same consumer. Consumers will have different attentions depending on which device they use. This means, your customers may potentially be looking for different things if they are using iPhone or going online from PC.
Therefore, when customers uses different device, marketers should reach their targeting customers not using the same approaching (e.g. not the same advertisement). In other word, the same person can pooled in a different target market based on the device they use.

I found this interesting that depending on the gateway, people look for different things even though they are the same person. The same concept could have been applied to pre-digital era (TV, radio, newspaper, etc), but now marketers can get data of every customers much easier than they used to and customers demands more from the marketer, the planning and how to reach target customers indeed should be done more carefully and it used to be. It may cost a lot (by losing valuable customers) for the marketers if they categorize their customers incorrectly.