One recognizes a usable book when one likes to use it.  A usable book easily becomes our everyday and lifelong companion.  It elevates oneself to a higher sense of humanity.  It stands as a testament of beauty.
The text of a usable book always sound poetic.  It just rings right.  It satisfies a need while bringing pleasure.  Its structure makes it stand on its own.
Good poetry replenishes by putting the mind to work.  Bad poetry consumates the mind to a task, a chore, a duty.