That incentive only works if a website's primary captcha use case is spam avoidance. Most websites that use captchas have a vested interest in preventing you fr

That incentive only works if a website's primary captcha use case is spam avoidance. Most websites that use captchas have a vested interest in preventing you from being able to bypass them by tossing money around. Paying to remove captchas is fundamentally unlike similar proposals (like paying to remove advertisements) that are designed to make innocuous users' lives easier because captchas aren't solely designed to prevent spam, nor are they designed as a passive revenue stream. For example, one common use of a captcha is, essentially, rate-limiting in a non-spam prevention context. It's arguable that rate-limiting should be implemented differently, but captchas are actually fairly effective for rate-limiting regardless. Websites that feature things like gift card numbers typically put captchas on lookups and validations to prevent people from simply brute-forcing them (especially if they do not use gift card pins). In scenarios like that, you don't want spammers to be able to bypass captchas, but if they fundamentally can, at least it costs them money. On the other hand, explicitly supporting captcha avoidance as a revenue stream, however, presents malicious users with the same opportunity that parents get if you offer to fine them for being late to pick up their children from daycare. You've just implicitly given them a choice that was not really allowed before, and they'll happily pay you directly instead of the shady API they have to use to get rid of the captcha. So to sum up - captchas aren't fun, but in principle you really don't want there to be a consistent method for cheaply bypassing them (whether grey market or officially supported) if the expected value of doing so is significantly higher than the cost.