When I started my publishing company in 2008, I had a lot to learn so I bought about 40 books about publishing.
Many of the books about self-publishing were self-published and many of them were extremely ugly.
They had terrible typography.
The worst sin was bad justification.
The lines of type in this blog are like most blogs and websites, a growing number of magazines and some books. The type is flush left/ragged right. "Rag-right" is much easier to produce, and many people accept it.
Justified type has a more formal, polished look. Ragged is obviously less formal. People can rightfully claim that justified type is abnormal and artificial, and ragged right is normal and natural. Text from typewriters (remember them) is normally rag-right. Some typewriters can justify, but the result is usually ugly.
A lot of very ugly justified type gets printed, particularly in newspapers with narrow columns (below). This old newspaper clipping shows lowercased "avenue" and "street." Apparently it was deliberate, not accidental, and was the official 'style' for the paper.
That's not enough.
A book needs a human touch.
You must carefully examine each line in each paragraph on each page so you can improve justification by changing words, spacing and hyphenation.
It's a lot of work and takes a lot of time to do it right -- but it's the right way to produce a book. (See exception at bottom.) There's no easy way. There's no shortcut. You must invest the time to go line-by-line, over and over again, or your book will look like crap.
Compromises are often necessary and every book I've seen has some problems with justification. Self-publishers seem to have many more problems with justification than professionals do -- and the self-pubbers may not even know that they goofed.
I purchased U-Publish.com 5.0, co-authored by Dan Poynter. This book has no hyphens, and the word spacing (below) is atrocious.
A self-publisher has an extra burden to produce a high-quality product. Self-pubbed books are initially suspect and must prove their legitimacy, and a bad self-pubbed book reflects badly on other self-publishers. Ironically, the ugliest and worst-written book I’ve ever seen tries to give advice to self-publishers. It was apparently never edited, or checked by a human being at its publisher.
The limitations of the Internet create the need for typographic compromises. As people get used to typographic abominations online, those abominations may become more acceptable in print. However, just because you can get away with ugliness, it doesn’t mean you should.
IMPORTANT EXCEPTION: Most ebooks allow the person reading to manipulate the text, so there is probably no point in trying to achieve nice justification. Ebooks designed for reflowable text and user-selectable type size can produce some terrible-looking pages. Shown below is part of Treasure Island by Robert Louis Stevenson, from a Kindle edition.