I read everything on a kindle, use kindle highlights, and then when I am done with the book (or even better, while im reading it) dump the highlights into Anki and create different cards from them -- this method has worked well for me for the past 3 years. I plan on doing it for the rest of my life.
Could I ask how you dump the highlights to an external service?
I guess he is using a technique similar to those posted in this SO post. [1]
Google tells me there are some third party libs/api's to do this, but nothing official, ISFICT.
[1] https://stackoverflow.com/questions/5374045/how-to-access-ki...