Feedback for The book of OpenLayers3

Finally I have decided to use LeanPub as the platform to publish my book. Here you can see the public page with a description about it: The book of OpenLayers3. Hope within a couple of weeks I can publish a sample chapter.

 What do I need from you?

What I need right now are your feedback, your opinions and reviews.

• What do you think about the book description?
• Do you like the cover image?
• How much would you be willing to pay for it?
• ...

I need you to be critical with mine to make a good job.

Thanks !!!