deadsea - 11:21 am on Jun 1, 2012 (gmt 0)
I recently expanded the translations of my website from 10 languages to 40. With the 10 languages, I occasionally had users contact me with translation corrections. So when I launched the additional languages, I made a feature where users can submit corrections, similar to how it is done with this Google feature.
As far as uptake, I get about one user a week that corrects a significant amount of text in one language. I also have links to the sites in the different languages, and get SEO traffic on them. So I have a user base. Its unclear to me how many users use Google's "translate a site" feature.