One common thread you see come up a lot in Yahoo! Publisher Network forum threads, especially at DigitalPoint Forums, as partnership threads. Partnership threads are threads started by "publishers" who cannot get a Yahoo! Publisher Network account for one of many reasons and asks to partner with one who has an account.
Why can't these publisher's get accounts? Can be because the publisher is based outside the US, and Yahoo! currently does not allow any country outside the US participate in this program yet. It can be because their site was rejected. It can be because they had an account and it was suspended due to violation of the terms of service.
It worries me when reading these threads. Here is an example of a recent looking for partner thread.