Left hand menu, down the bottom, they have labeled their Adsense Link Unit with "EzineArticles MarketPlace". Now isn't that a no-no?
I saw a very big site (PHP script site) asking people to click their ads. I don't want to get anyone in trouble, so I won't mention any names..but if one of their competitors saw that they could easily just report it and kill the entire business model of that site. Very risky..
More than 1 million page view per month(data many months old) they are premium publisher. You can see their adsense ads quite different from other sites. Google allow this only on premium publisher. Once you are premium, you can Bend a lot of Adsense ToS. Google become your helper not the boss. You must have seen this on www.askmen.com and www.myspace.com as they write adsense as sponsored links and there is no mention of prevalent words on net the "ads by Google". Thats what happen when you become premium. Google, yahoo and MSN try to lure you, not the other way round.