As we've said in the past, Yahoo is working on a new search advertising interface that will provide businesses with a more powerful, easier to use advertising experience. We plan to introduce the new interface during the second half of this year.
However, today, one user posted a thread suggesting Yahoo! Search Marketing is actually testing the new algorithm out. The forum thread is at Search Engine Watch Forums and states;
Yahoo! seems to be performing some sort of test on certain accounts - one being my personal Yahoo! account. It is my guess (based on how that I see the rankings changed) that they are testing a pricing model similar to Google and MSN in which rank is a combinatin of CTR and max bid.
Wow - but Yahoo! denied this!
Forum discussion at Search Engine Watch Forums.