In the last few years we have seen eye tracking become ever more popluar, the biggest shift being that rather than having to sell it as a new innovative biometric methodolgy to our clients,  it is now being asked for as part of their briefs

Market Research.
Marketing professionals rely heavily upon marketing research to garner insights into customer opinions and behaviour. Conducting a market research study based solely on asking participants to explain why they did or did not engage with a branding message or environment is unscientific and inaccurate.
Participants may be able to formulate an answer to their visual behavior; however, visual attention involves conscious and unconscious impulses. Therefore, participants may not really understand their own visual behavior, resulting in participants creating inaccurate explanations for their patterns of visual attention.
Eye tracking is incredibly effective at reading these non-verbal reactions to stimuli.
Researchers are able to glean important insights into viewers' engagement with marketing material through analyzing visual behavior.
As a result, researchers are turning to eye tracking more and more to find the real answer as to why consumers behave the way they do.
Below is a video of shopper browsing and selecting products as they go about their weekly shop.