I even have a business called Rent A Book Reviewer that provides pre-publication critiques
I recently posted an online critique for a book on a website that announced the book.
Although some may see my critique as "unmerciful," the author realized that I was right, and hired me to be a copyeditor.
Back in the 60s I became the copyeditor on my college newspaper, the Brown & White at Lehigh. While my main motivation for becoming "copy ed" was to keep others from butchering what I had written, it turned out that I really liked copyediting, and apparently I did it well.
The skills I developed editing in college helped me later in the 'real world' when I worked as a magazine editor, advertising copywriter, journalist -- and author.
There is probably no page, paragraph or sentence that can't be improved by chopping or shifting some words. That's part of what a copyeditor does. Other duties include fixing grammar and spelling errors, and maintaining editorial "style" -- such things as making sure "5:30pm" is not on one page but "7:15 AM" is on another page. The copyeditor has to have a good memory, and sharp eyes to notice a missing close-quote, wrong font, oversize or undersize indents and extra spaces between words.
- While every author must edit her own work, I think you can become a better writer if you try editing someone else's work. Without your own ego protecting the sanctity of your words, you can be unmerciful, and the techniques and tools you develop will improve your own books.
This exercise may not lead to a second career as an editor, but you'll probably become a better writer.
I've written a (bestselling) book about editing your own work which should also help you edit others' work. It's called Self-Editing for Self-Publishers: What to do before the real editor starts editing or if you're the only editor. If you find it useful, I'd appreciate a complimentary comment on Amazon. If you hate it, write an unmerciful critique. I can take it.