What about traffic? I know about your paid traffic, but what about organic?
Find a few long tails for a common problem your book will assist with and hit'em hard.
A linked network supporting your cause wouldn't hurt either in the future. A Wordpress blog will work fine, with the right theme.
WP blog- you can write pages/posts that lead to different sales pages that appeal to different markets. Your incoming links can link to your homepage or individual pages/posts for targetted results that appeal to a different set of values.
Or, interactive copy might work well ( I think I sent you a link for a program that creates the forms and runs the script for that a while back) where your copy goes into a series of questions or plays on certain motivators (emotions) that the prospect selects, which then directs them to a relevant sales page. Two/three step process, kind of like what you have now.
Link love to your blog....
^^sn's - squidoo, del, digg, linkshare, kabootle, this list is long and these aren't all of them...
Propeller.com
Slashdot.org
Digg.com
Technorati.com
Del.icio.us
Stumbleupon.com
Twitter.com
Reddit.com
Tagza.com
Fark.com
Newsvine.com
Furl.net
swik.net
Connotea.org
Sphinn.com
Blinklist.com
Faves.com
Mister-wong.com
Spurl.net
Netvouz.com
Diigo.com
Backflip.com
Rawsugar.com
Bibsonomy.org
Folkd.com
Linkagogo.com
Indianpad.com
Plugim.com
Myjeeves.ask.com
Buddy Marks
Connectedy
MyLinkVault
Google Bookmarks
Jumptags.com
Fetch
OYAX
A1 Webmarks
Bookmark Tracker
myVmarks
Mixx.com
Wirefan.com
Danogo.com
Links Marker
Symbaloo
Ximmy
Health Ranker
Ka-Boom-It.com
^^maybe some article writing...
Ezinearticles.com
Articledashboard.com
Goarticles.com
Articlecity.com
Easyarticles.com
Articlealley.com
Articlebiz.com
Ideamarketers.com
Articlecube.com
^^Vid's have high pr, so record a couple -
Sclipo
Sumo.tv
Youtube
Google
Dailymotion
Blip
Metacafe
Yahoo
Facebook
Myspace
Vimeo
Revver
Veoh
Vsocial
Photobucket
Putfile
(mass submission could be a good idea, but do the big boys manually...youtube, google, etc)
^^ Landers, opt in, RSS
Build a link funnel with the above, all leading back to your blog.
Why not your main website? The blog is the beast, the powerhouse, whereas your main site should be considered with more care and precision. The purpose of the blog is to find the traffic, and get in front of it. Have you ever tried stepping in front of a freight train? Just as in life, you may only get one shot to make the correct decision.
Then, you delicately use that power to sort your incoming traffic by needs. Teaser content for each tail that sorts the target incoming traffic will gladly link to the appropriate presentation for your product. In short, same product, twelve different ways to market it and presentations. Each, crafted carefully, will appeal to a certain genre of your market.
This way, people have searched for that tail already, so they have the desire, you give them the solution, make things exciting with the benefits (it's about their luck, NOT YOURS!). That should pull like a mofo compared to a generic "wanna be lucky?" page.