Promoting Books Online
I got asked recently by the author of a popular-science book about the brain for some tips related to promoting his book. As a Canadian, he's having the same experience I am: major media exposure (resulting in large sales) in Canada, and much less attention in the States. Here's what I had to say:
The U.S. is a very tough nut to crack. I get major media in Canada, too, but have a hard time getting anything in the U.S. As I'm sure you know, the best place to promote books in the U.S. media is probably NPR; for your book, an interview on NPR's Science Friday with Ira Flatow would be a natural (it's the counterpart of Quirks and Quarks here); I've been on Science Friday, and it's a great show. Another good one for your book (and my current one, Rollback) is A Touch of Grey (seniors of course are interested in brain function, and over-50s are the biggest market for hardcover books, because they have the disposable income). They did a great, in-depth interview with me recently.
Your website is good, but it lacks the two things that have driven the most traffic to my own site. Number one: an actual sample chapter of the text. People don't want to read ABOUT the book; they want to sample the book. For my current novel, I'm giving away 10,000 words out of 100,000 online; in your own case, at least one case-study chapter online would be appropriate.
Number two: something that's value-added. The biggest draw for my website isn't the stuff about my books per se; rather, it's the stuff on how to write and sell science fiction.
In your case, a few brain-teaser exercises might be useful, or a checklist to see if you've lost any of your cognitive function, or whatever. People don't link to sites that just promote books (if they really want to point to your book, they'll point to its page on Amazon); rather, they link to interesting, useful, or fun things they think others should check out.
Also, a blog helps; the net is all about social interactions. See how Tom Stafford and Matt Webb are selling (their very interesting) book Mind Hacks, for instance.
Best of luck!