>If it's informative, you can't really summarize. Something can be informative, but still longer than necessary. A lot of non-fiction books could do with 10-50

>If it's informative, you can't really summarize. Something can be informative, but still longer than necessary. A lot of non-fiction books could do with 10-50 pages, but marketing wise they won't sell because people feel they don't get enough for their money. So the authors are prone to extend the contents to an amount of pages people are willing to pay for. Let's say 200.