Wear a sandwich board everywhere you go.
Several things:
First, I hope it is not free!
Second, I hope you have a grabby title. Thirdly, I hope you have a grabby title, and fourth, I hope you have a grabby title.
Have you investigated the Amazon connection on this? They may take 35% (I think) but the remaining 65% on hundreds of thousands of copies could be a serious wad in your pocket.
Do you have a blog? Be an only slightly obnoxious blogpimp.
If you have no blog and no intent to create/maintain one (it IS work) then comment on other peoples’ topic-similar blogs and if you are too shy to promote your item directly, then try to incorporate phrases particularly if the appear in your title. You sell 25K ebooks for $3 (cup of coffee = a no think transaction) and Amazon takes a buck, you could make $50K. Yes you could. it is a FABULOUS business if you can get it going and they do all the work for you.
Above all...spend some time on the title! The title could be wroth several tens of thousands of dollars to you.
And start writing your next one!
Facebook. Find pages devoted to adoption and push it. It works. I got a book deal with a publisher from Facebook networking. Also set up a page of your own book and reach out to friends and family. Good luck!
It takes time to make Goodreads work for you, but it is where a huge chunk of the ebook action is:
http://www.goodreads.com/author/how_to
You just did. Tell us more.
Matt Bracken aka Travis McGee has written several thrillers about a corrupt government that sells the people out.
Here is the first: http://www.amazon.com/Enemies-Foreign-Domestic-Matthew-Bracken/dp/0972831010
I consider Travis McGee to be a foremost authority on this subject (but only after I bought all of his books on Amazon!)
I promote my physical book by writing articles for related blog sites. Also, another great idea is to participate on podcast interviews. And of course having a web site is also important.
Stick something in your tagline for a start.
Laz you have an ebook?
Pinging Travis