The word is out that as of next week, Yahoo! will no longer allow pay-per-click advertisers to bid on competitors' trademarked terms. Yahoo!'s long-standing policy has been to allow for such bids, so long as the ads landing page clearly outlined the differences between the company's own product and the trademarked term that they bid on.

A key example of this practice is the Mazda PPC campaign that capitalized on Pontiac's encouragement to "Google Pontiac" at the end of all of their television commercials. Mazda, seeing an opportunity to pick up some easy traffic began bidding on Pontiac related phrases and linking in to a page that compared the Mazda MX-5 to the Pontiac Solstice.

It's important to note that the new rule will not impact web sites that actually sell other people's trademarked products, or that provide substantial information about them. That means that a small business that resells Apple iPods will still be able to bid on the term, but the Sony Walkman Bean site could not.

Yahoo!'s keyword policy will change on March 1st.