A survey of released Friday by the Pew Internet & American Life Project found 83 percent of U.S. search engine users rated Google as their preferred search engine. That was up from 47 percent in 2004, the last time that Pew gauged people's attitudes about Internet search engines.
Yahoo's search engine ranked a distant second at 6 percent, according to the latest numbers, down from 26 percent in 2004.
Google Inc. has turned its dominant position in Internet search into a gold mine. The company's Internet search engine is the hub of an advertising system that generated $36.5 billion in revenue last year -- up from $3 billion in 2004.
But the Pew findings also indicate Google may be risking its popularity by trying to learn more about users in a quest to sell more advertising.
Nearly three-fourths of search engine users said they don't want search engines to sift through their personal information to deliver results tailored to their individual interests. Google has been doing this more frequently since January when its search engine began to include personal information pulled from Google's social networking service, Plus.
More than two-thirds said they don't want to be targeted by customized ads because they don't want their Web surfing activities to be tracked and analyzed.
Google might be vulnerable to a backlash if its major rivals, including Yahoo Inc., Microsoft Corp. and Facebook Inc., didn't also collect personal information to help them aim their ads at the right audiences.
Google and its rivals say they offer a variety of tools to protect their privacy, including ways to erase their search histories. But only 38 percent of Internet users are aware of these privacy-protection options, Pew found.
Whatever privacy fears might be nagging them, most people remain comfortable using search engines. Pew found 59 percent of online Americans use a search engine at least once day, up from 29 percent in 2004.