Don't you hate it when you're reading and something happens to grind the story to a halt? I don't mean those annoying phone calls, household interruptions, or any kind of external demand that has the reader reluctantly setting the book down. The stop I'm referring to is something in the book that diverts the reader's attention from the story.
The most common stops these days are caused by poor or no copy editing. Self published books have a bad reputation for spelling, grammar, and other assorted copy errors, but they're not alone. Most of us can skim over an occasional such error, but more than a few and the spell is broken, the story loses its luster. Concentration is broken.
The success of a book is measured to a great extent by how well it can maintain an illusory world, an alternate reality for the reader. When the illusion is broken and the reader's attention is diverted to something else the story becomes less satisfactory.
Typos and writing errors are not the only stops that diminish the reading experience. Poor research is a killer. Facts concerning history or geography matter. I recently read a book that placed a particular group of buildings I happen to know well, in the wrong town.
Lately there seems to be a competition to see who can invent the most weird names for their characters. That's fine if the names are pronounceable, but if they're just cutesy versions of better known names, or words I have to stumble over each time they appear in print, there goes the alternate reality while I stumble over how to pronounce the jumble of letters. It's understandable that writers want to give their characters distinctive names, but there's a difference between distinctive and mumbo jumbo.
While we're reading through our manuscripts for a final check before submission, it would be wise to check for stops. If beta readers have to ask how to pronounce a name, it's the wrong name. Beta readers should make note of anything that causes their minds to wander or distracts from the flow of the story. It's important to keep errors to a minimum, but it's also important to just plain eliminate those annoyances that bring our stories to a crashing halt.