> You can't use ReCaptcha (or any captcha) for ads. Captchas work because they prevent access to content users want until they solve the captcha.
If you've used ReCaptcha in the past few years [1] you might have noticed it often doesn't ask you to solve a captcha. The parent is describing using a similar approach of detecting bots to identify ad impressions that shouldn't be counted (spam).
If you've used ReCaptcha in the past few years [1] you might have noticed it often doesn't ask you to solve a captcha. The parent is describing using a similar approach of detecting bots to identify ad impressions that shouldn't be counted (spam).
[1] https://security.googleblog.com/2014/12/are-you-robot-introd...
(Disclosure: I work at Google in ads, though not in spam.)