I previously praised dice as a great way to get interviews. It's better than I knew.
In the first few weeks of job hunting, I submitted my resume to one of the SuperMegaIncorporated companies you find around here. I honestly don't remember if I submitted my resume at large, or to a specific position (they have hundreds if not thousands), but either way I never heard back. And as far as I know, my resume is still lying in a virtual drawer, being eaten by virtual beetle larvae, or goats. But the goats can have my resume, because a recruiter at SuperMegaIncorporated found my resume on dice and would like to talk to me about a position. Not a position I'm qualified for, mind you, but if I limited myself to jobs I qualified for on paper I'd be ruining my wrists testing video games for $9/hour + pizza.
(Note to recruiters: here I am using humor to lighten the stress caused by having exactly the wrong amount of previous work experience, and the subsequent difficulty. I am, in fact, an excellent worker and you should hire me right away)
This brings me to another advantage of recruiters and job posting boards: they know what they want more than you know what they want. Until you're at the write-your-own-ticket stage, you're never going to find a job posting that you fulfill every stated requirement. Corporations know this, and there's usually some give in the system, especially if the position goes unfilled for a long time. But you, the lowly job seeker, has no way of knowing which requirements are optional and which are actually required. Letting them do the sorting can save you a lot of time. Of course, it costs the company a lot of time, but that's their own fault for writing ambiguous requirements.
One last note: a lot of places say they require "A BS in Computer Science." This is bullshit. My BA has raised eyebrows exactly twice, and both people accepted it when I explained that I'd fulfilled exactly the same requirements as a BS. And according to a flyer put out by the advising department at my school, you don't even have to major in CS, just take some classes in it. This is the same department that allows people to major in Medieval Literature, so take it with a grain of salt, but there it is.