1. Introducing website to my friend by chatting or emailing, but not telling them anything about Those Google Ads on my site, not encourage them to click - Does Google see it as SPAM?

If your friend starts clicking your ad's you may get caught out. This is called FRAUD not SPAM. Google will throw you out of the program.

2. Promoting my site by Link exchange: sending my website information to the link parter, May google see it as SPAM

Link exchanges are part of the way the web works. This is just promotion not SPAM unless of course your link request emails are automated and unsolicited. This has nothing to do with the way google views you, your site or your account.

3. Place my site on Wikipedia with Relavant content, but if someone report it to Google. Does Google see it as SPAm?

Why would someone report your site to google? when the SPAM is on wiki? Wiki will see it as SPAM and throw it out but that has nothing to do with google.

Ska

3. Place my site on Wikipedia with Relavant content,

If it is relevant and unique and accepted by the Wiki, no problem. If it is Spam it will be rejected anyway.

Thank you all for your replies.

Actually, it is so terrible to get banned by Google, so the aim of my post is To lear & DO everything to Avoid this Bad.

But I still have some question: if Google found FRAUD or SPAM, will they ban us immediately or wait for sometime?

Thanks,

Kurt

I have also heart about "Yahoo's Adsense". But I think that Google still the number one.

There can be a delay in a ban for upto around 6 weeks. As I understand it, you lose all funds in your account - no come back. And once you get a ban - it is nigh on impossible to get back in. It sounds to me as if you are a bit concerned you may have breached some TOS - perhaps I am wrong. If for example a friend has been clicking on your ads - it will almost certainly result in a ban....if this is the case, you could try and notify them in advance and say you believe that someone you know has possibly been clicking, and try to avoid the inevitable. Else, sit and wait!

Thanks for your comments Trannack, I dont know whether someone I know have been clicking on the Ads or not, but I have tried to tell them not to click on any Ads but the internal links. I have emailed Google to notify about that and I do hope that they will understand my case.

So I have experienced one thing that: I should NOT tell anyone about my website...it hurts me rather than helping me.

Regards,

Kurt

Getting traffic through relevant links is one thing, but those "traffic exchange" programs out there are just exchanging meaningless, completely untargeted traffic and are very subject to abuse of all kinds.

Thanks Google Adsense Team, they reply me so quickly.