You could capture your visitor's emails then offer them affiliate products within that niche. As it seems your cost per 1K visitors is pennies, Adsense wouldn't be your primary income source. If you take 170K people, then let's be realistic 5% could be your email subscribers; that's 8.5K people inside your email, ready to click on links you want them to click. You've spent a long-time on the blog. There are other ways to monetise.