signor_john - 7:31 pm on Jan 31, 2009 (gmt 0)

But I know there are some guys still doing YSM to adsense, so I am here want to get the secret to not be considered as spam by google if using YSM to drive traffic, if I am lucky I will get the answer

You won't get a definitive answer from other AdSense publishers, because (a) the fact that someone's getting away with something today doesn't mean he'll get away with it tomorrow, and (b) in aany given case of suspected click arbitrage, the intrinsic usefulness of the landing page or site to the reader is likely to be taken into account, and you have no way of knowing how Google would judge your site in relation to whatever benchmark Google and its employees are using.

Bottom line: If you can't get an answer from Google, you'll need to rely on your own judgment and decide what level of risk you're willing to accept.