People complain about (traditionally) published books being rife with errors. I’m not sure where this complaint comes from, to be honest. I come across an occasional error, and I think there may be some sloppily converted ebooks out there with a lot of errors resulting from the conversion process, and for anyone who’s paid good money for a book like that, my sympathies.
My pet peeve is the non-word “alright” slipping into published books, even bestsellers. Name of the Wind, I’m looking at YOU. State of Wonder, I’m looking at YOU. I suppose it’s inevitable that “alright” is going to end up a real word eventually, even though I despise it, and you will never, ever find it in one of my books. (The correct form is “all right.”)
But as for typos and such, a lot of care is taken to make sure those don’t slip into the book. Gambit is currently being proofread by three people, myself and two in-house proofreaders. It’s a little under 400 pages, including the promotional material at the end, and I’m proofreading 70 pages a day in two sessions of about 35 pages (so my eyes don’t bleed). I keep sessions short so I stay alert–the whole point is not to miss anything! In my first 70 pages I found two actual errors and one thing that’s a continuity problem between book 1 and book 2. Some errors are introduced in the copyediting process. Most are from the original manuscript.