In addition to sending my second draft to my agent and to my writing group, I often send it to beta readers. These are people who will read the whole thing for me and tell me what they think. I’ve used these readers less and less over the years, because after my writing group and my agent, there’s not a lot of need for yet more feedback, but there are always friends who want to read my books just because, and so I still send it out occasionally to a few.
These readers will give a different perspective than the writing group, since the writing group is going through chapter by chapter. A beta reader will have a better grasp on the overall fluidity of the book. In my experience they will almost always like the book more as well, because it’s more pleasurable to read a book at your own pace than it is to read one chapter a week, and probably also because they don’t listen to everyone else’s complaints as they go. Perhaps because they like the book more, they tend to make far fewer comments than the writing group, which is why I find writing groups so invaluable. But beta readers are fun. They’re experiencing the book the way you want a reader to experience it, and it’s nice to hear from people who read the book quickly and enjoyed the experience. It reminds me of why I wrote the thing to begin with: because I have stories I wanted to share.