Some 85 percent of searchers using a brand name as a query reach that brand's website - but search results sidetrack the remaining 15 percent to the sites of competitors, affiliates and comparison shopping engines, writes ClickZ. It cites a new study from Hitwise, which noted that 75 of the most popular 100 searches in February involved trademarked brand names - up 17 percent from February of last year.

Queries containing a brand along with related search terms, not just the brand term alone, pose a similar concern, according to Hitwise, which suggests that marketers need to ensure that not only the brand name but also related terms result in searchers' ending up on their sites. For example, 83 percent of searches for "allstate" ended up on the brand's sites, but only 74 percent of searchers for "allstate insurance" did so.

Yahoo recently changed its keyword policy to allow only brands, resellers, information sites and comparison-shopping sites to bid on trademarks. Google allows others to bid on brands, but does not allow them to use trademarked brands in the ad creative.