Google has quietly introduced a new feature, called search-within-search, that is alarming some big-name Web publishers and retailers. They worry that users will be siphoned away through ad sales to competitors. What Google is doing is offering a secondary search option if the user initially searches explicitly for one of the brand-name destinations that Google has identified, such as "Best Buy." This secondary search lets users refine their query entirely within the pages of the desired site — but using Google's search, not the site's, and showing Google ads on the result pages, quite possibly ads from competitors. "Analysts generally praise the feature as helping users save steps, but for Web publishers and retailers, there are trade-offs... 'Google is showing a level of aggressiveness with this that's just not needed,' said [one Internet consultant]... Take, for instance, a [test where] users of Google searched The Washington Post and were given a secondary search box. Those who typed 'jobs' into that second box saw related results for The Post's employment pages, but the results were bordered by ads for competing employment sites like CareerBuilder or Monster.com. So even though users began the process by stating their intention to reach The Post, Google's ads steered at least some of them to competitors. Similar situations arose when users relied on Google to search nytimes.com."