Companies spent significantly more money advertising online in 2004 than in 2003, as ads linked to search-engine activities proved to be the most popular category for the second straight year.Internet advertising revenue in the U.S. reached US$9.63 billion in 2004, up 33 percent from 2003, according to a report released Thursday by PricewaterhouseCoopers LLP and commissioned by the Interactive Advertising Bureau.Moreover, 2004 broke the annual revenue record set in 2000, further proof that online ad spending has roared back after difficult times in 2001 and 2002. Online ad revenue has increased in eight of the past nine quarters. For more on this increase visit here Also for discussion on increase in internet advertising visit this forum