Pay for traffic!

Hi all,
Has any one used or had experience of using pay for traffic services like those on webtrafficzone or trafficblaze. And what about morethantraffic.com? Sounds too go to be true, and most probaly is. But its quite tempting!
Any comments would be must appreciated. I'm fighting with my common sense here, and at the moment the temptation is leading...

I know its not really about PPC or even SEO, but found no other suitable forum

You will get more traffic through those services, but is it traffic you want? SEO/SEM is about getting relevant traffic in order to convert that traffic to customers, members, etc. To spend money to get just traffic is a waste of money. I would rather spend that money on PPC, relevant links, or...

...Perhaps! Or just letting people know you exist!
Some of those services say $10 for 10,000 visitors. Thats 10,000 people seeing my completely new site (if i were to have one).

Ok... if you want 10,000 meat eaters to visit your vegetarian only site... go for it. That same $10 spent on PPC might get you a customer or two.

Surely it depends on the kind of site your talking about. Suppose you have one about news, or a general forum. If you mean 10,000 visitors who were looking for vegatarian food and found your site offering them grilled sheep brain, then I can really see your point.

How is this traffic generated?

Also assuming anyone "SEES" your site at all. Sometimes a "hit" doesnt invlve human eyes. I would rather spent $1000 for 1000 targeted visits than $10 for a million "hits."