I decided to do an interview with Google after being contacted by a recruiter, but I think I applied for something so it wasn’t a cold contact. Not getting me to apply, but getting me though the process to get a job offer.

Google recruiters are also much better than those at Facebook, who were much less interested in getting candidates through.

Many internal recruiters at companies also work in the HR department, typically they are also the first contact for perspective hires and usually are in sync with the hiring manager needs.

Some recruiters do outreach and networking events (most common at feeder schools through job fairs or internships).

You can have people applying, but not the right people applying, so you get recruiters to go out there and persuade people to apply.

Yes, usually trying to get the word out, that their new interviewing process is not as onerous as their old one.