Our common-sense model of memory, particularly long-term memory, is that it’s like a reference book or a hard-drive – something that we have to go and consult. We go in order to (try to) retrieve something from memory, a bit like going to the library to borrow a book.
But our memories are being used every second, on the fly, in real time. Your ability to read these words depends on this. When you were very young words looked like boring bits of black scribble (and you noticed the pictures instead), as a child you worked hard to get these letters and then words into your head, now they are there and they can be accessed in a micro-second. You can’t help yourself noticing words, you can’t stop it even if you try, but if you want to notice the font shape, or the ink or the pixels then you have to try so much harder. Some things are incredibly easy to notice, others aren’t.
When someone looks at a shelf of brands, or down a street at a range of different shops, they don’t notice half (or more) of what’s there. Some things are so hard to notice, not because they don’t stand out, but because the viewer doesn’t have the necessary memory structures in their head.
One person sees two trees, the other sees an oak and and elm.
When marketers think about noticing they think of things they can do to try to grab attention. Which is fine. But for many this means bright colours, stunts, something NEW, price discounts and so on. Now there is nothing wrong with trying to grab attention with such devices but we have to also remember that noticing depends on memories. If you want your brand to be noticed then you need to build and refresh consistent brand memory structures. Changing a logo is more likely to get you noticed in the marketing press than on shelf.
It’s the same for advertising. Most ads aren’t noticed, or not noticed sufficiently for them to build or refresh brand memories. You need a clever advertising agency to create content that is attractive, that gains some attention, but if you are only relying on the creativity to drive noticing you will fail – people have to notice your brand not just the creative content of the advertisement. To do that you have to work with what’s already inside their heads. Which means undertaking careful research to document existing memory structures, to understand your brand’s distinctive assets.
Marketing Science 
ByronSharp, Thanks for the well written article, it was inspiring and powerful.