People know who you are. Good. It doesn’t mean they will buy your book.
You have unreal expectations. Yes. You have. You expect all your friends, colleagues, virtual friends, or any person showing some interest in your person to buy your book.
Bad news: they don’t care about how hard you worked on your book. If you expect some kind of gratitude for being in their life, you won’t get it.
It’s a new world. If you’re good at writing books, you’d better be good at marketing your books and, most of all, yourself. Figure out how to spread your ideas and consequently have people interested in knowing more and buy your book or go home.
Learn from people that explain with a sound analysis how to be better at writing or marketing your book. Stop listening to people that tell you it will not work just because they know better. And the most important: analyze and measure everything you do. Keep doing what works. Remove from your to-do list what doesn’t. Analyze and measure again.