This doesn't appear to be a self-service platform judging by the stated specs (integration with 3rd party networks, etc.) and "contact us" form -- probably goes to the ad sales team to start a manual sign-up process targeting large clients.
I was interested in the "audience" description on that BN page ... female, 40, kids in house, college educated, income $60k+. I know that when I used to run Goodreads Giveaways the respondents skewed heavily female. That could be because of the topic areas of the books, but I also suspect it speaks to the audience composition at Goodreads. I wonder if it's similar at Amazon.