CoachCV
CoachCV was a service I operated in 2003-2004, offering to review and correct CVs for free. Users would upload their CV to the website I had created and I would respond to them within 24-48 hours. More than 400 CVs have been submitted and reviewed... for free!
I came across a number of "interesting" (read: terrible) CVs, as well as the CVs of a few people whose job is among other things to help students with their own CV creation.
The way I had made the service known was very simple: I emailed the student career department of universities in France and mentioned that I was happy to help students with my free CV review services.
I would potentially revive this service and see if it could become a paid one. It could come combined with a job interview simulation service, especially considering my extensive experience in that domain (more than 300 interviews given at Google and an active member of multiple hiring committees).
Update, March 2019: and the new service is live!