These can be successful if you direct the hits to a sharp, short lead capture page offering a bonus for signing up.
One of the problems is that they can easily be faked. That's why there's so many companies out these selling 10,000 hits for $29.95 or less!
If you want to try this out, I would use Adminder. I've used them in the past, and I know they are reputable and they don't count pages that are never seen because of pop-up blockers. So unlike other companies, you'll actually get the hits you pay for.
If you want to go to a bargain company, you won't have any trouble finding one. But make sure to put a "break out of frames" code on your landing page to make sure you dont get ripped off.
Put the following javascript in between the <head> and <title> tags in the top of your webpage:
<script language="JavaScript"
<!-- supplied by http://www.hypergurl.com -->
<!--
if(parent.frames.length>=1 {
window.top.location.href="index.html"
}
// --></script>
Good luck!
