I watched your video and calculated the productivity. In the video, you started solving captchas from 0:39 and stopped at 2:10, and that's 91 seconds in total. And you did 28 captchas (27 successes because there was one failure at 1:59, but let's forget about that one). So averagely, a captcha needs 3.25 seconds to be solved (91/28), and 18.461 captchas can be solved per minute (60/3.25), and 1107.66 captchas can be solved per hour (18.461*60). So actually, the productivity is about 1107 captchas per hour, not 1900+ per hour.