Earlier quoted context omitted.
Serious question: Why would you want to highlight or annotate a small sample of a book?
Maybe you found that section particularly interesting and would like to look back at it later? Maybe you're reading the book for a class and instead of taking notes in the margin, you're taking notes on the Kindle. I actually find myself highlighting stuff all the time. You can also see areas of the book that other people highlighted, which adds a kinda neat social aspect that isn't usually present in reading.
I didn't mean highlighting in general. That I get. I meant highlighting a sample of a book.