We treat all author support issues to hello@leanpub.com as confidential, of course. For author support issues which are fine to discuss in public, you can see our author forum at https://community.leanpub.com/c/authors ... If you look there, you can see a representative sample of the issues people have had recently. (I don't want to turn this HN thread into a Leanpub author support forum thread, of course! However, our authors typically seem pretty happy with our service...)