I did as they said at the bottom and gave them my e-mail and other personal details so I could download the eBook that they were giving free preview copies of - "Building Microservices". Unfortunately, they sent link to PDF only so it's not usable to me. Just a heads up to others so you save yourself the time of discovering that. (I'll just wait for when the book is finished and then I'll buy it so I get ePub. I like O'Reilly and have bought many books there before.)