I recently read a mystery published by a small press--let's keep names and titles out of this gripe. The writing was fine in many respects; the chapters were short, the pacing was excellent, the characters were sympathetic. The plot and dialogue worked well.
So why mention it? Because apparently no one proofread the manuscript. Wouldn't you think that if a novel is about a kidnapping, that someone would notice that there are supposed to be two p's in kidnapped? It's spelled wrong dozens of times, because no one thought to look up the word. Frequently the author is too close to catch these errors, but someone should catch them before the reader does. Running a spell-check program would have caught "kidnaped" or "kidnaping." Even the spell-checker is not sufficient, but it should be a writer's first line of defense.
Typos--at least typos in quantity--distract from my enjoyment of a book and from my appreciation of its author.