And cheaper for freebitco.in to implement so hopefully more money can be used back into the site (there must be a lot of money wasted on the captchas)...
reCAPTCHA is a free service from Google for a site so it doesn't make any monetary saving. The only cost involved is for botnets to solve them.
Is it!? Theymos said he paid $0.10 for captchas (maybe that was with the old service though). I always thought the free captcha was just a sales technique to start with although it is bad enough that they probably kept it free.