Most non-fiction books that I've started and quit reading before 25% was because they felt like the content that could fit in a blog post had been stretched to

Most non-fiction books that I've started and quit reading before 25% was because they felt like the content that could fit in a blog post had been stretched to over 300 pages. I've found that summaries can give you quite a good idea of what the book is about in most cases. I read the full book if the summary interests me.