I've had a lot of this as well. I don't think it's a scam (though I wouldn't know since, like you, I just ignore those calls). The positions these people are recruiting for seem awful to me, which would explain why they're hard to fill (and why the company is using a seemingly cheap service to fill them).
Yeah, I agree.. well I have also gotten some emails (from seemingly similar types of "recruiters") who do some sketchy things such as asking me to fill out a form with SS#, etc, obviously these go right to my spam box.
This is sort of what Sleep No More http://sleepnomore.com/ is doing and it's pretty successful. It's also in a place where that sort of thing can thrive.
