Three tweets doesn't build enough context
for me. A product in the book space needs to express a passion for books and that's hard to do without acting as if books are worth the investment of time spent reading. I think of BookTV and the New York Times Sunday section and the back of
The Nation.
"Let me tell you about this great book" can't be pulled off in 200 words. If that's all you have to say, it wasn't that good.
Frequently, there will be an "Ask HN: Where Can I Find the Hacker News for X" Usually I think, well that would be Hacker News. But as I was writing my reply, I thought 'a Hacker News for books just might work". Push the big idea about which you have passion harder. Good luck.