It is unfair to ask Virus to divulge his sources of traffic. That is proprietary business information that he has worked hard on through blood, sweat and tears...or more accurately through money and time invested in testing, testing, testing.
I understand your frustration but the honest answer is that without you testing yourself you will never find the information that will truly make you successful.
I personally have learned a lot from reading both redtide and Virus's threads and posts on the topics. The biggest takeaway is that if you find a source that produces conversions but not a ROI initially, it most likely is a winner and just needs to be refined.
Test, measure, then test again and you might just find yourself with a goldmine

. Good luck friend.