Small nitpick, but to be clear: Craigslist is a for-profit company, and has been registered as such since 1999. The job listings cost money to post. That's where the site is believed to make most of its revenue.
The .org domain, and the fact that a lot of users haven't experienced posting a job, create the popular misperception that CL is a nonprofit. To be fair, it's a strange kind of company, and I'm not sure if profit is its overriding goal, per se. But it's a for-profit enterprise. It may be the most laid-back for-profit I've ever seen, though. :)
You can't beat them by being just a little bit better.