Amazon's Search Inside urges one user to look at a given page, plus two forward and two back, with a limit of 15% of all the pages in a book before it says you've seen too much. Google likewise permits five sequential pages, but tests have shown one user can view 85% of a book's pages.

Five pages (let alone 15% or 85% of all pages) often lets one read an entire short story, a poem, a whole recipe in a cookbook, a relevant section of a reference book, etc. These rigid one-size-fits-all solutions are thus too permissive.

On the flip side, these rigid systems prevent authors who want to have more of their work readable. Many authors would like to allow 75% even 100% of their work to be readable online. Some books could be 99% readable online, but for a few pages that need to be blocked for contractual reasons. These rigid one-size-fits-all solutions are thus too restrictive.

These current implementations are thus "one-size-fits-few".

The solution, both legal and from a user experience perspective, is to allow copyright owners to determine which pages of their work they wish readable for free. Copyright owners know their works best. This only works if they have control on a per-book and per-page basis.