This is all too true. I've lost a lot of respect for book cover designers, especially those who throw an image together from five stock photos (swirling crows in the sky commonly appear) which looks more like a ham-fisted collage than a believable scene.
I've mentioned this practical joke before on the Colony, but the next time you're in a chain bookstore go to the crime/thriller section and rearrange the stacked paperbacks to show a crowd of silhouettes walking away from you. See how long it takes an employee to rearrange them.
I swear that some of these dark figures appear on several different books, which makes me wonder all sorts of imponderable things to do with modelling—some models specialise in hand shots or leg shots, so is there a subclass of models who look good only from the back?! I know why they have moody figures walking away, for not being able to see their faces, means that the reader can make them look any way they like, but wouldn't it be refreshing to see a book cover design with the protagonist charging panic-stricken towards you, about to jump off the paper?
Coincidentally, I've just started reading a novel whose cover fits the Heavyweight literary fiction category. Joseph Connolly is a writer I've been meaning to tackle for a while (and he has a really impressive beard!), and as I'm 64 next month, I thought I'd try his This Is 64.
I have to say that, while I hate covers that scream stock photos, and it's fun to poke fun at the cliches, there is a real argument for creating covers that tell readers what to expect inside. The cover isn't an artistic statement, it's a marketing tool. And I suspect that if a reader has enjoyed one book with a woman's silhouette and swirly typeface, they're going to gravitate toward other books that look similar. Understanding how those book cover cliches sell books could be valuable, because readers do judge a book by its cover.