Do you find the Captcha feature in the comments area annoying? (That's the feature that requires you to type in two words.) I had no idea, but each time you're doing that, you are helping with the digitization of books. When the OCR digitizing the book cannot recognize a word, it sends that word to CAPTCHA and then all of who use that feature "teach" the computer what the word actually says. See this Ted Talk video, starting around 3:00.