They also buy books from authors whose work they've enjoyed before!
It's official now. There was a survey and everything. Notwithstanding Richard Curtis, and the editors who look for "packages" to promote, notwithstanding all the fancy promotions and publicity campaigns, "nothing sells [a book] better than the recommendation of a friend or relative."
So here at Comma Central we did a deeply un-scientifical survey. I asked my co-workers "How did you choose the last book you read for fun?"
Editor #1: "I had read a short story by that author, so I borrowed a book by the same author from the library."
Editorial Trainee: "My sister recommended it to me."
Production Manager: "Someone gave it to me, and it sat on my shelf until I finally picked it up."
Big Boss Editor: "It was by an author I had read and enjoyed before."
Yours Truly: "I remembered my Spanish teacher in high-school recommending this author, so when I saw one of his books at the library, I picked it up."
Editor #2: "Friend's recommendation. I could lie and say it had to do with a stellar publicity campaign, though."
Experience would indeed support the survey's findings.
Quoth Rachel: In other news, the sky is blue.