I saw a post by prolific novelist and author Derek Haines (Australia and Switzerland, his site here on how to sell self-published books, using blogging as a tool, shared here from Twitter.
He starts out by suggesting a blog on some practical consumer issue (how to get cheap fares) to draw readers, and then by putting ads or Amazon widgets on the blog. Along those lines, it seems right now that the widgets he's talking about are available only to Wordpress, not to Blogger (where Amazon seems to have dropped support in August 2015). I'm still looking into this.
I like better the plan of a blog that continues the substance of the issues you deal with in your book(s), even if fiction. That could mean multiple blogs.
Anyway, Haines also distinguishes between marketing and "selling".
I know, that because of the nature of my “Do Ask, Do Tell” series, I’ve made my text free online for those who want it. Do I undermine sales? In the practical world of non-fiction and policy, probably not, because people buy policy books when they want to anyway. (But the last part of DADT-III is indeed “fiction”).
What I don’t think is terribly effective is just setting up a site to sell the book (probably designed by a third party) and leaving it at that. I think you need to continue following the issues that drove you to write.