I can see their site, but the login button is gone. I think someone has screwed up their flash menu. Anyone know what the login url is?
It totally depends on the site/traffic/type of visitors. Some sites work well with Kontera, some don't. I have a gaming site where the visitors are on average 14-16 years old, they don't have CCs so affiliate programs aren't much use, and they won't click AdSense or Chitika (or anything else). But for some reason they're happy to click Kontera. I've found that Kontera also works well in forums, as long as you don't overdo it.
How much traffic to you get the your site(s)? I personally wouldn't suggest using Kontera on anything with less than 1000 uniques per day. Have you done any research into your site's demographics? Once you find out exactly who your visitors are, then you can try and work out why they aren't (or are) clicking.