ReCAPTCHA is used on millions of websites to verify human users. Given the massive scale and visibility of these widgets, it looks like a potential goldmine for impressions. Yet, Google has never added ads to it.

Considering their focus on ad revenue, this seems like a missed opportunity, or maybe a deliberate decision.

Was it an ethical choice, a UX concern, or a legal limitation? Or is it that the data collected through ReCAPTCHA is already more valuable than showing ads?

Curious to hear your thoughts.