At the very least, it "saves" your game between sessions, so you can continue where you left off. I wonder if anyone has made a book to be read this way so you can easily know where you stopped reading?
Hmm, this could be kinda nice, especially if you want to ctrl+f search for a previous passage, without the risk of jumping ahead and spoiling yourself. I wonder if any ebook readers (software or devices) have implemented that specific feature.