Spaced repetition is the model about how your memory works the author claims do not exist. With Anky I know exactly how much I retain of everything and how much I forget, with graphs and all.
So now , every time I acquire something new I must make an allocation in the future for rehearsal with Anki.
Another very useful thing is fast reading. Your mind can read extremely fast provided one detail: You use always the same layout standard format, then your subconscious can read multiple lines at a eye glance(after lots of training of course).
Every single book has a different format, and most of the time is not suitable for fast reading, with things like long lines that make it impossible to make sense of multiple lines for your mind.
So in order to make them useful I have to parse them and display on a standard way.