I think before spending money on advertising or trying to get the book into the hands of more book sellers, the question is how to reach out to people that aren't part of your spheres of influence. Your die hard fans, like those who have already supported you via the kickstarter or who hang out here in permies, have already bought your book or will do so eventually. The next groups you want to reach: where do they hang out, online or off? What are the podcasts they listen to or the mags and blogs they read? Who are the people in their interests that they follow on social media? What facebook groups do they hang out in?
In my mind you ought to spend time doing outreach with the next group over that may be interested in the similar stuff, for example survivalists (or people who love their work). What podcasts with preppers and wilderness minded people could you reach out to and be guest or post on their blog? How about environmental minded podcasts or DIY?
How about money savers, like the early retirement extreme? Mr. Money Mustache comes to mind.
Then we think about people who are further away from your spheres, like cooking and food, maybe self-publishing groups. Motivational self-help (since you're arguing that we individually can change the world).
Then, there's the general public or the people and spaces who are likely to disagree with you, but may welcome you on their podcasts, blogs, youtube channels, in order to debate or argue with you. These are the people with audiences that ultimately you want to persuade since they likely never heard about you or permies.com.
And of course there's things like NPR.
So why do these things rather than jump directly with the advertising, or getting indie bookstores to carry your book? Well, advertising is expensive, and book blog tours and such probably doesn't connect you with a topic specific enough for you to leave your mark (other than books). Your strengths lie in the conversation and your hope is to persuade audiences. Indie book stores are nice, but the numbers of people who go and browse just aren't what they used to be. Slim pickings in my mind for the time and money involved.
