Book Buyers as a Market Demographic

This is a follow up to yesterday, as it's been stewing a little more in my head. In the NYTBR article, if I recall correctly, one of the quotes mentioned that if there aren't reviews in newspapers, then people aren't going to know about books. My gut reaction was, "Actually, newspaper readers aren't going to know about books." I find the notion that all people have access to newspapers--or choose to read them--as suspect as the notion that all people have access to the internet--and choose to use it.

So here's my question of the day: of the newspaper reading demographic, what portion of them are book buyers? Of the book buying demographic, how many of them read newspapers? Knowing how those two markets intersect would be a really interesting twist on this conversation, and might show a more solid argument in favor of why keeping book reviews in newspapers is important to the publishing industry.

As a sub-thought: I do understand why some people feel more comfortable with book reviews that are actually chosen and viewed by an editor before they're published, rather than simply trusting an online source that doesn't appear to have that clout. I'd actually trust a review that went through an editor more than I'd trust the more personal blog reviews that I write. (My School Library Journal reviews, for example, are more concise, professional, and targeted than what I write here--which is far more based on my own opinion rather than taking a particular audience into account.)

But is there any reason why a book review source online couldn't follow that model? Maybe some of them already do. More food for thought.