how do I get accurate results from several search engines?

I've tested a couple of campaigns and have found that only a bit more than half of them have the "traffic source" listed. The rest are blank. Apparently yahoo was sending traffic from other sites (content network?) even though I had content turned off.

That got me thinking about what would happen if I was running ads in google, yahoo, and msn content network and 3rd tier ppc engines. In that case I don't think hexatrack would be able to tell me where the traffic was from in most cases. I couldn't tell which campaigns were converting or not.

What do you think about this? I can only imagine that I'd have to make one campaign for google, one for yahoo, one for msn, one for ask, etc. which would get totally out of hand for multiple campaigns. Is there a better way?

We do show you referring URL's.  The best way would be to see which of those sites converted and then visit that page.  Look for your ad and see which network is actually showing the ad for ya.