From Android Police:
Let’s be honest, busy people don’t have time to trudge through long books made of mostly filler. Unfortunately, publishers know they can’t put a high price on a 40-page book. In the end, authors are stuck building a lavish sea of meaningless words around the simple concepts they want to convey. That’s where Blinkist comes in. It’s a service that boils popular non-fiction books down to their most formative and salient points. Think of it like Cliffs Notes, but even shorter and not funded entirely by high school students.
. . . .
Blinkist suggests you can fly through Guy Kawasaki’s The Art of the Start in 18 minutes and Phil Rosenzweig’s The Halo Effect in just 13. Each book has a brief description and hints about who might want to read it, and all of the content is laid out in simple sections with just enough text to get the point without a bunch of repetition or unnecessary examples. There are currently over 400 books in the catalog, with about 40 new books added each month.
Link to the rest at Android Police
To answer an obvious question, copyright protects the expression of ideas, not the ideas themselves.
17 U.S. Code s102 (b) states:
In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work.
The distinction between an idea and the expression of an idea may not always be clear but, for example, the idea of a young man going off to a boarding school where magic is taught and magical creatures are kept is not protected by copyright law while Harry, Hermione, Hogwarts and the particular world created by Rowling is protected..