Startup #7: Book review website aggregator

I've always been dumbfounded as to why there's no book review section on metacritic. For those who aren't aware of metacritic, this is what the company has to say on itself:

"Metacritic.com achieves its stated mission--helping consumers make an informed decision about how to spend their money on entertainment--by providing access to thousands of reviews in a number of entertainment genres. We feel strongly that multiple opinions are better than one, and also that the presentation of these critical opinions must be done in a concise, organized and easy-to-understand manner in order for them to be useful. We also encourage our users to dig deeper on matters that interest them by providing links to full reviews whenever possible. Finally, we believe firmly in providing a pleasant, popup-free user experience for our visitors."

It's a brilliant concept: aggregating all available reviews into one reliable score for comparison; but where is the book section!? They do Film, DVD, Music, Games, and TV. Someone really could takeover the book review aggregating website niche immediately, with no competition. Perhaps follow the Rotten Tomatoes template as a guide, since it achieves the same effect as metacritic but only applied to one medium: movies.