'YOU'LL GET ONE EMAIL FOR 8 DAYS AND THAT'S IT.'

I believe you don't want to/would not send any more emails, ads, any of your product spams etc (since you make clear by saying "that's it") then why not give whole thing at once and without asking for emails?

At the end of content, you could include an extra chapter explaining about paid course. By giving at once, without requirement of email, a lot of people would download the course.