In case you haven't heard, you can earn some CAPTCHA tokens, for doing as the name suggests, Captcha puzzles. Here's the link: https://captcha.steemwhales.com
I use the past tense because i think that as the site becomes more popular, the Captcha provider is rate limiting the number of puzzles. Like it will force you to solve 5 puzzles before allowing one through. Annoying.
You will be asked to try again and if you're unlucky enough, you will hit an error message. Only got that once though. I hope it's temporary.