"Craigslist will generate revenue of almost $700 million this year [full year 2016], with a profit margin around 80 percent — making it the most profitable classified advertising site in the world, the AIM Group reports in its Global Classified Advertising Annual."
"it managed to increase revenue by 75 percent in 2016 over the estimated 2015 total"
https://aimgroup.com/2016/11/29/craigslist-revenue-soars-aga...
Story from May 2017 talking about how well they're doing:
https://www.forbes.com/sites/ryanmac/2017/05/03/how-does-cra...
The AIM Group's long term chart on Craiglist's estimated revenue, year by year:
https://i.imgur.com/cAwd2T3.jpg
Obviously we'll see how Craigslist fairs over a longer period of time vs Facebook market. However, Craigslist is a free listing service for the typical user, as such Facebook is a modest threat - people can trivially list on both services.
