When popular tales began to be printed cheaply in pamphlets known as chap-books and sold by peddlers, their popularity started to wane. It is helpful to draw a distinction between the telling and the reading of stories. The former is much more likely to hold the attention of the audience and have a greater impact. Moreover, in the language teaching classroom, you can adapt the story to cater for the level of your students by telling it instead of reading it. There is a strong case to be made for not pre-teaching new vocabulary when story telling unless it is absolutely essential to the enjoyment of the tale.
Stories are above all for enjoyment.
As teachers of English we want to exploit them for language purposes, but we must take care not to milk them dry and kill the joy. Dealing with new vocabulary as it arises, gives you the chance to present it in context, elicit its meaning, and then give the students the opportunity to transfer it to another setting. It helps to break the story up into more manageable chunks and enables you to involve the class more actively in the story-telling process. Moreover, a few words unknown to the reader can add effectiveness and local colour to a narrative. One of the justifications for the use of storytelling in the classroom is its global nature as an activity.