27th May 2020 - 12:25:03 - 1178 characters

On NPR's How I Built This on reCAPTCHA and Duolingo with Luis von Ahn:

  • Created CAPTCHA and gave it away for free to Yahoo
  • His research focus was on crowdsourcing, eventually creating both The ESP Game to label images and reCAPTCHA to annotate scanned text
  • ReCAPTCHA was inspired by the realization of how many hours a day humanity was wasting filling in CAPTCHAs
  • The New York Times paid $42,000 per year of the NYT archives annotated and ReCAPTCHA was able to burn through a year of data per week
  • ReCAPTCHA was acquired by Google
  • Duolingo eventually went ad supported and had a paid tier to remove ads
  • Approximately 3% of the 40 million active users are paid subscribers at $10 per month
  • Makes almost $500,000 per day on average, spiking from $400k to $600k due to COVID-19
  • Once social restrictions were implemented in China, usage of the app doubled, with this pattern later seen across the world
  • Duolingo is now valued at $1.5 billion