What makes a great book?

At a glance, this is a dumb question: what makes a great book, if it's not great writing, an engaging plot and believable, complex/rich characters? Well, while I'm sure all that helps, it's evidently not enough to get published... I mean, have you noticed how much crap there is out there, lining the walls of bookshops around the world? Sure, there is also a lot of good stuff out there, no question, but the fact remains that just because a book is published, it doesn't mean it's good.

A few weeks ago I picked up The Historian by Elizabeth Kostova. I had just read that it was quite long (over 200,000 words) and that Kostova had had a $2 million advance -- both things quite unique for a debut novel by a completely unknown author with zero external awards/publication credits to her name (sure, she won some little internal award from her MFA program, but whooptee-freakin-do... who hasn't?) Anyway, I was intrigued and I bought the book, thinking, 'hey, if an agent didn't shrink away from a 200,000+ word opus by an Great Unknown, maybe the book was THAT good'... So I just HAD to read the damn thing...

Well, I just finished it last week, and, no... It's definitely NOT the greatest thing ever written. I wouldn't even qualify it as a 'brilliant' book by far -- and I've been reading all my life (literally -- I learned early and haven't stopped since). Don't get me wrong: it's an engaging read, and some of the language in it is quite nice and everything, but overall, I found the book repetitive and predictable and the climax was, well... anti-climatic at best... Most importantly, I found the characters to be little more than props in the service of the 'quest' theme... They're not people with layers and complexities and whatnot... They're all very plasticky, puppety... Wooden. And although I'm normally a big fan of the correspondence narrative (i.e. stories told in letters), Kostova milks this way too much, to the point that the technique loses credibility completely. Ditto for the story-within-a-story-within-a-story-within-a-story-within-a-story schtik. I mean, I can suspend my disbelief once to accept that a character would write a bunch of letters that he/she knows will never be sent... But this is repeated not only twice, but over and over and over again by three or four different characters... Not only does the technique lose any potential impact, but the characters start bleeding into each other, further losing their already tenuous 'personalities'.

Still, this unremarkable debut novel by an unknown author not only got accepted by an agent and a publisher despite its length... It sold for a $2 million advance... How did this happen? Sure, the theme is marketable enough, but... is THAT enough? What happened to rich, complex characters? To a compelling, intricate plot? To prose so beautiful you could cry? (In all fairness, though, there IS some nice language here and there throughout the novel)

In other words, I'm confused. I bought the book to figure out what made it so special... And I just ended up with more questions than before.

I guess all an aspiring author can do is sweat bullets in hopes of writing a great query and hope like hell that it will be read by the right person at the right time. Art is, after all, subjective; and market trends are that -- trends...