Never a wasted moment.
From the Article
Congratulations are in order. You, yes you, dear reader, have been part of something incredible. Thanks to your hard work, millions of books containing pretty much the sum-total of human knowledge have been successfully digitised, saving their texts for future generations. All because of you.
No, seriously.

You know how occasionally you’ll be prompted with a “Captcha” when filling out a form on the internet, to prove that you’re fully human? Behind the scenes of one of the most popular Captcha systems – Google’s Recaptcha – your humanoid clicks have been helping figure out things that traditional computing just can’t manage, and in the process you’ve been helping to train Google’s AI to be even smarter.
And you thought you were merely logging into some website or other.


Recaptcha (or “reCATCHA” if you prefer) started out as a collaboration by a number of computer scientists at Carnegie Mellon University in Pittsburgh, first released in 2007 – and it was quickly snaffled up by Google in 2009. The premise was as described above: by marrying up users who need to prove they are human to data that needs transcribing, both sides get something out of it.
So instead of digitising books by having one person carry out the very boring task of typing or checking a whole book manually, instead millions of people can unknowingly collaborate to achieve the same goal. Remember how it always used to be two words you had to enter? Conceivably, only one was the “real” test, and the other was a new word that was yet to be transcribed – but as the user you wouldn’t know which was which, so you’d have to attempt to do both accurately.