Jack Hoadley, author of Antarctica to Footscray: Arch Hoadley A Man of Inspiration and Courage found book launches to be a useful strategy:
Since the book launches (which I found particularly successful) I have concentrated on sending copies for Review in relevant journals and getting some summary paragraphs into newsletters which I thought would have an interested audience. I tried to tailor the paragraph to the relevant niche. Mixed success but I have received several requests from the Antarctic community.