You guys haven't had a bust yet? We are getting hammered right now.
You might have saw my post on the blue links.
Jakob Nielsen preaches it and it still works.
I guess we'll see the blue link thing keeps working because a lot of sites use the default (hence the blue) link color.
As long as it is enough to keep the general public thinking "blue == link" it'll work.
::emp::
If you're using YPN for arbitrage, make sure you use the Reporting URLs feature. It will tell you what sites are performing and what sites aren't. This feature keeps track of impressions, CTR, RPC, etc for a given url.
YPN takes a day to update these stats, but they are extremely better than shooting in the dark and guessing which sites aren't performing.
Doesn't adsense do that too? Adding URL channels should do that for you.