Source: F-Secure Weblog
F-Secure has a brief report showing that Russian CAPTCHA cracking services offer a thousand CAPTCHA solutions for $1. These services are used to mass-register things like Gmail accounts, protected by CAPTCHA, for abuse purposes. And, ironically, Google's sponsored links include advertisements for CAPTCHA cracking services when you perform a search for terms like "crack captcha" or "break captcha". So, if Google's CAPTCHA fails to stop abuse, then they are at least getting a slice of the black-hat profits.