If you enjoy reading, !Books is pretty active place to discuss what you’re reading and review it or get recommendations.
I try to post significant price drops routinely to !ebookdeals as well. I mostly post ones that I have heard good things about / read myself and really enjoyed and are valid at all 3 big US ebook retailers, Kobo, Barnes & Noble, and Amazon at the same time or Humble Bundles. There’s no rule against others posting deals they endorse for other regions or other books, I just wanted to avoid it being a firehouse of spammy links and I only shop US Stores.