Google’s paid search leadership is clear in this at least: both MSN and Yahoo are following their ad console set up.

Google’s paid search account structure is set up with Campaigns and Adgroups (sub-accounts) below the Campaigns. The Adgroups contain keywords with ads associated with that group of keywords. Bid position is based on a number of factors to include your maximum cost per click and your click thru rate.

Yahoo’s system is different than Google’s. Yahoo has only one layer they call Categories and are straight bid to position, click thru rate is not a factor. Each keyword has its own ad.

Find out more about the Yahoo Adwords competition at http://www.searchenginelowdown.com/2005/10/yahoo-direct-traffic-center-and-msn.html.