My industry is weird (it's in my post history, so I'll just say it, it's EMS). A lot of ambulance companies don't have someone to actively maintain a website. They might have a website but it might be a year or two out of date. It's easier and cheaper for a supervisor to make a "we're hiring! Email me your info!" post on Facebook, especially when that's where everyone is anyway and that's how everyone else is doing it. It's a very informal and very odd industry.

We have to do so many hours of continuing education every year to maintain our certification and I have a co-worker who does the coolest trainings. I finally asked how he finds them because all I can ever find is the dryest, most boring classes. Of course the answer was Facebook. It's all on Facebook. If you want to get into a new specialty, if you want a fun training, if you want to connect with providers who aren't in your immediate circle, if you want to learn a new niche or find a company or a job across the country you need Facebook.