covers definitely matter. My 1997 book BEYOND THE BEYOND from St. Martin's Press got fantastic reviews when it came out, but it was doomed from the get-go by a hideous cover.
When my editor sent me the cover, I was horrified. I called him up immediately.
"There's a giant penis on the cover of my book!" I said.
"That's not a penis," he replied calmly. "That's a rocket ship."
"I've seen rocket ships, and I've seen penises," I said. "That is definitely a penis."
"Lee, You don't understand cover design, marketing, or publishing the way we do," he said. "Leave this to the professionals."
"It's a penis and it's against a bright yellow background," I said. "No bookstore in the country is going to display this book. You're killing the book before its even published."
"We've been publishing books for a very long time," He said. "I think we know a little bit more about how to sell books than you do."
So they went ahead with the cover. And when I went on my book tour, one bookseller after another told me the same thing -- "We can't display this book, there's a penis on the cover! What were you thinking?"
The book got terrific reviews from the LA Times, Entertainment Weekly, Publishers Weekly and many others.. but the sales sucked and I never sold the book into paperback.
I blame the penis.
I learned two lessons from this. Publishers don't know any more about bookselling than I do... and people DO judge a book by its cover.
Lee