trader said:
How does TrafficZ do that successfully?
Personally I don't know how they do it, but they manage it, at least for previously registered domains.
For an example, I picked up otomobilim.net when it dropped in August 2003, three years ago, and it still/now shows up in position one in google.co.uk out of 90k pages.
I'm guessing that in the case of this domain, part of the answer for the "success" is that there are still plenty of sites linking to it.
trader said:
Which categories do well there?
I'm not too sure about that as I put very few domains elsewhere. I'm sure that some people do know though.