Lots of people got banned due to this. People driving traffic from Adwords to AdSense sites might be guilt of arbitrage. Only if the page quality is not good. Follow the link Are there any types of websites that merit low landing page quality scores?
If you have quality contents than its ok, but if you have sites which is just made for adsense, then you will be banned in few days.
This is a regular practice, and many people have been succesfully running these type of campaigns but the main thing is to be done according to guidelines of google.
Exactly! I have yet to hear from Google, and I have asked. It seems they want to leave it up to their own discretion. Which is no foundation for a business model on my end.
Good decision, since there are many cases of people being banned for adsense arbitrage and there isn't a clear pattern.