Can you judge a book by its cover?

I'm in the process of designing the cover to my new children's picture book but how important is it to get the cover just right?

They say you can't judge a book by its cover, but as an ebook, the cover and the description are the only two things you can judge it by.

Also, when designing a cover for a children's book, who are you aiming to please, the child or the parent/carer? Is it the picture, or the wording that is most important? What colours please most?

So, please help me with my designing - can you judge a book by its cover?

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