I downloaded it first "without honor", puzzled why he wanted my email. Then I tried entering my details sans email, and was rewarded with compliments to my character – it seems email is not required.
It would be better for the author's information collection, and friendlier to readers, to indicate that email is not a required field – otherwise people will assume giving email is necessary, as in a zillion similar forms online. And/or explain why email is wanted.
I'm the author. In all my free books I have collected email addresses only for very rare events. How rare? In 15 years of publishing free books I've only used the books' email list once: I used a previous book's list to let people know that Edition 2 was available.
If you put in fake information, my little collector is none the wiser. Or just click on the "without honor" link, which is really there so Google can grab it.
