This post on Northern Planner got me thinking.
I may be splitting hairs, but I think we give the modern shopping environment considerable credit for creating behaviour that is hard wired over millions of years. We have evolved as "cognitive misers" - basically, the brain is designed to minimise the use of precious resources beyond directed activity. This is the mechanism behind habit, or why you'll occasionally find yourself standing in the kitchen without the foggiest idea why you are there.
For most people, grocery shopping (specifically - other forms are different) is an incredibly low-interest activity. We are directed towards getting in and out as quickly as possible. It is not a question of ignoring or filtering what is going on around us. We literally do not see it. Our brain does not allow us to see it, because the effort of noticing, processing, ignoring and carrying on uses precious resources that we don't want to waste. The same phenomenon drives "banner blindness" and dothetest.
The implication, obviously, is that everything that works for a while stops working after a while. Which is a bummer - and makes me think that "Blade Runner" may have owed a bit more to agency planners that Ridley would like to admit.
"Try something new" is a great effort to address this, but the consistency of Tesco's yellow and red special offer shelf wobblers are a master stroke. They have penetrated the brain that so the consumer stands in front of the fixture and instinctively looks for that money-off signal, before grabbing their usual brand and heading to the freezer aisle.
That is part of the reason why brands are built over years, not quarters.