When chosing a book you don't know by reputation you usually use the cover/blurb on the back/first few lines as a guide but apprently this is all entirely redundant and the key to knowing if a book is actually worth committing too is on page 99.
Some guy called Ford Madox Ford (yeh, for once that's not my subbing, his name has "Ford" in it twice) will launch the website page99test.com next month to prove this theory. He's asking authors and would-be authors to upload page 99 of their books and ask for reader feedback.
His theory is that the first few lines or pages of a book are written like a sticky trap to get you hooked but a far better way to judge the strength of the story and the quality of the writing is on exactly page 99.
The book I have beside me now is Lights Out in Wonderland by DBC Pierre and it supports the theory. Page 99 is a spectacular sex scene in an oversized fish tank which is home to a giant octopus. This book might not be the perfect litmus test though. It was as addictive as the cocaine habit of the main character and I think you could open it on any page and want to read through to the end. I'll give the idea more of a thorough work out next time I'm dusting my book shelf.