Branding is the big word in publishing these days, even if you aren’t writing a series. Take the latest novel by my friend Loraine Despres. 
She wrote a terrific, highly-acclaimed novel that came out last year called THE SCANDALOUS SUMMER OF SISSY LEBLANC, the cover of which is to the left (click for a larger image) . Her new novel THE BAD BEHAVIOR OF BELLE CANTRALL isn’t a sequel, but you wouldn’t know looking at the cover. 
Because the publisher created a distinct look for Loraine’s first novel, they were able to repeat it for the second and establish a visual "brand" for her (I bet if she wrote a dark crime novel for the publisher, they’d probably use the same cover style). Will the branding work? Who knows…but have you noticed how similar the covers for Anita Shreve‘s last few books have been? It’s obviously been working for her. I hope it does for Loraine, too.
That stock cover photo is all over the web. You’d think they’d use something original.
This is a terrific website. Thanks so much for linking to my website. By the way, THE BAD BEHAVIOR OF BELLE CANTRELL is a prequel to THE SCANDALOUS SUMMER OF SISSY LEBLANC. Belle is Sissy’s grandmother. In the first book she’s a septuagenarian suffragette, who does not suffer fools. In BAD BEHAVIOR she’s a hot young widow living in a very turbulent time.