On a related subject, the only recruiter I've ever interacted with that I thought was earning her paycheck (she cold-emailed me) was from Facebook. Her email showed that she had done some research on my startups and read through my (public) Facebook profile, discussing some of my favorite hobbies (motorcycles and travel).

I still declined, but I actually wrote a nice response instead of dustbinning it as spam.

I suspect a lot of what differentiates a good recruiter from a bad recruiter is the ability to connect on a personal level. Even though it's obvious what the motivations are, it's still better to [pretend to] be human. Perhaps the recruiting field needs to draw some lessons from online dating.