We wanted to let you know that a limited number of keywords that are currently linked to synonyms, or “mapped,” will soon become unmapped keywords to give advertisers more control over them.
As you may know, we use various matching technologies to link some bidded keywords to other terms that a searcher might use synonymously to look for them. This mapping connects some keywords with related synonyms, such as “car insurance” with “auto insurance.”
Recently, advertisers have voiced a need to manage some of these synonyms separately. this is so that they can use separate bidding and creative strategies, tracking URLs and business goals. To give advertisers more control over their ads, we will remove a limited number of keyword mappings on 7/29/2008.
What does this mean for your accounts?
Your advertisers may still receive traffic for these terms through the Advanced match type even after these terms are unmapped. For better control, however, we suggest adding these “new” terms to your advertisers’ account, along with new tracking URLs, bids and ads.
From the Yahoo Search Marketing Team Received 7/17/08