You do. Logos are a very effective visual shorthand.
You probably just don't realize how much you rely on logos, until the product or business you look for by sight, suddenly ends up looking different and you either can't find it, or don't recognize it.
Tropicana's sales this year (2009) have fallen 20%, down $33million (though there is no hard evidence that this is linked to the pack change)
Yeah .. right ........