Former bookseller angle is a nice touch. My one worry as a reader: at ~500 words a day a normal novel takes half a year. Can I dial the pace up, or send myself the next drip early when I'm hooked and don't want to wait until tomorrow?

You can keep reading as much as you want, there's a button at the end of the email that sends the next installment.

There's also an option to send multiple times a day.