This story may be apocryphal but it rings true to me and illustrates how illuminating and valuable blind tasting can be.
Some years ago the Symington group of port producers launched an entirely new product, Warre's Otima 10 year old Tawny, packed in an extremely jazzy-looking half-litre. obviously designed to appeal to a younger-than-average wine drinker who might otherwise not think of themselves as a port enthusiast. They did very well with it and has been a runaway success in terms of volumes sold.
But every time it was submitted to wine competitions, notably the International Wine Challenge I believe...