There is return on investment even if it is not monetarily. Users or reCAPTCHA or Duolingo also do work for for-profit companies as well.
From the article:
> “Some people ask ‘Why do you work for free? Why do you spend so many hours a week doing this mapping?’ ” Hidalgo said. “You feel good about knowing that the people who drive around everyday save time because you are investing your time in fixing the roads and doing this mapping.”
From the article:
> “Some people ask ‘Why do you work for free? Why do you spend so many hours a week doing this mapping?’ ” Hidalgo said. “You feel good about knowing that the people who drive around everyday save time because you are investing your time in fixing the roads and doing this mapping.”