Preferred cost bidding allows advertisers to set a preferred bid objective rather than a maximum bid. Google AdWords then does the work that a bid management system would have otherwise needed to do, in order to maintain the bid at an average value specified by the advertiser. The positioning will be calculated similar to the way it is with Max CPC or CPM bidding.
Another cosmetic change introduced this week is the integration of Google Website Optimizer as a link on the “Campaign Management” sub-menu in AdWords. Functionality to split test landing page creatives gets integrated into the AdWords system now with the addition of this feature, as shown below.
Interestingly, this feature does not currently work for agencies working on an account via their AdWords MCC (My Client Center).