Information . . . or . . . Advertising
The Associated Press has publicized some of the results of the Pew Internet and American Life Project. Among other interesting tidbits, Pew found that only 18% of Internet users can tell if a search engine result is a paid listing or the actual result of their search.
Only 38% of Internet users know that there are paid listings displayed on the results pages. Of the 38%, not even half say they can always tell the difference.