Why should I use a CAPTCHA web service and not my own home-brew ones?
CAPTCHAs are created to differentiate real human users from automated scripts. Some CAPTCHAs can be solved by advanced computer algorithms. A common workaround is the outsourcing of CAPTCHA solving to human agents in developing countries. By using a CAPTCHA web service, we can constantly monitor the quality of the CAPTCHAs we are generating and instantly adapt them if we see they have been hacked. We also use a reputation-based system to monitor the people solving CAPTCHAs, allowing us to block the outsourced human CAPTCHA solvers. Sorry for that guys ;)
