Can anyone shed some light on why logos and names matter so much. I know they do because millions of dollars are spent on getting these right. But I cannot see myself consciously saying "Nah ! I wont be their customer I don't like their logo". But I must be doing it at a subconscious level.

I can understand associating a small picture with a company. Its something like cash: transfers perceived value from one location to the other. But why does not any form that is moderately memorable do.

What I find hard to understand is that a little tweak here and there apparently has a huge impact. Not talking about he new Starbuck logo, just in general.