I violated one of my own rules when I checked this book out of the library.
The adage that "you can't judge a book by its cover" may have been true once, when all covers were more-or-less interchangeable. It is not true now. By looking at the artwork, the blurb, and the presentation, you can get a pretty good idea of the kind of reader that the publisher wants to attract. And by looking at the quotes, you can usually get a sense for how good it is.
That's because publishers want to make money. Given a selection of book reviews, a publisher will obviously print only laudatory excerpts. Furthermore, within that set, the publisher will prefer quotes from the most prestigious, influential, or high-profile sources. That is, they'll rank their potential sources in order of prestige, and take the top 3-5 from that list. If the topmost quote comes from the Cleveland Plain Dealer, you know that the book didn't get a good review (if any) from the New York Times. If the topmost quote comes from the Tulsa Herald, then you know it didn't get a good review from the Cleveland Plain Dealer.
And if the topmost quote comes from an Internet comment or Website--except this one, naturally!--scream and run away.
For The Fold, all the quotes come from authors. This is better than J. Random Netizen, but not much; it's like having your school's alumni office calling you instead of a telemarketer. I was suckered because the top quote is from Andy Weir, whose book The Martian was the most enjoyable SF novel of 2014. How bad could it be? I thought.
In truth, The Fold isn't epic-level bad; it's not interesting or ambitious enough to be epic-level anything. The first half is a stab at a straight-SF "what's going on?" kind of story. The gimmick is an ancient and hoary one, and at the best of times any reader with a measurable IQ would figure it out pretty quickly. In this case, however, there's a pointless prequel chapter which blatantly gives the game away ... on page 9. After which we spend the next 193 pages getting to the SHOCKING REVELATION that, yep, it's exactly what you thought it was.
The second half of the book takes a 180-degree plunge into action-adventure territory. It reads as though it's based on the movie Aliens, only with Marines who've gotten their gear and their tactics from the Imperial Stormtrooper Academy.
Oh, and one of those author quotes gives away the plot here too.
In his acknowledgements, Peter Clines thanks his editor. I'm tempted to ask "for what?", except that I think I know: this book could well be popular. It's got a standard-issue Smartest Guy in the Room protagonist, which we nerds always like. It's got the jargon of real science fiction, without any hard bits. It's got self-conscious nods to geek pop culture. It's utterly mediocre, without a single original idea or arresting concept, which means that many readers will enjoy it--much as I (at age 15) enjoyed The Sword of Shannara. In other words, the editor knew what he wanted, and got it.