Amazon crowdsources some work for humans that computers just cannot complete. Tasks often pay only a few cents to a few dollars each. If you have some time to spend and want to do what is usually pretty simple work such as completing identifying information in photos, to more complex tasks such as translations. You can always set up an account and complete a few HITS to get a feel for it. I’d done this many years ago when it was relatively new and was able to earn a few dollars, some people claim to easily make $50/day.