I think the rule is that you cannot use the 2 different accounts on the same page. DP uses more than 1 account on the same site (revenue sharing) everyday (here).
Section 2 of the Google Adsense TOS: so no, you cannot have 2 different accounts (publisher) on a same PAGE. website is ok as long as those 2 accounts don't appear on the same page. hope it's clear enough.
Just to double confirm. 2 different accounts on the same page is not allowed but OK on different page of the same website - one account for one page. Nobody will do that since you just can't give the bad ones to another account and take the good ones for your account.
i viewed to source codes of several threads. the client ID for the top ad changes ocassionally but the link units remains static. of course, this is inconclusive....just something i did out of boredom.
I think i can use the Adsense ads from another account using the Alternate ad URL? It won't be against TOS..
oh..so different accounts is valid in one website if the ads are being displayed on different pages.....oh i see