Again, I don't intend to say anything bad against these users but this is just an example that shows that "scambusting" is a very effective avenue to build reputation, maybe the most effective..
I am pretty sure there are much easier ways to "build" reputation:
1) do trade, use escrow - get trust (all 3 parties)
2) take smallest loans you can get, repay early - get trust
3) sell trinklets - get trust, send trust to everyone, make sure that people who buy from you will get positive trust so everyone who wants trust will buy from you.