I’ve placed a link on my will writing website to my book now as well and hope that helps a little, getting anything in front of Joe Public for free is extremely difficult and then getting it in front of the right people is even worse.
As usual, the only effective way to do that is to pay for advertising to your specifically chosen target audience and the trick is to do so at the exact time that they’re thinking of using your product or service, so it looks like I’m in for an expensive weekend!
Here’s the page I’ve created http://www.wills.org.uk/a-guide-to-writing-your-will/