Online advertising The volatility of Internet stocks says a lot about what is expected from them. It says rather less about the true health of the online advertising market. Carat, the media buying group, expects Internet advertising worldwide to grow by 25 per cent this year. In developed markets, growth rates are even faster. US first-quarter online advertising growth, for example, was 38 percent, and there remains plenty of room for further rapid expansion. Credit Suisse expects US online spending to grow at an annual rate of 22 per cent over five years, but that still leaves it with a total market share of about one-tenth. Demand from advertisers, however, is strengthened because people believe that online advertising generates a high return on investment. Measurement is never easy, but based on survey data from TNS Media Intelligence, online currently enjoys a return on investment of 26 per cent, compared with 17 per cent for magazines, the next closest category. Online offers the opportunity for manufacturers to reach a larger number of consumers. A recent study found that US food companies are increasingly using the Internet to target children with interactive games and commercials, which is a concern for anti-obesity campaigners, but an example of the potential of 'rich media'. With expected overall advertising market growth of only 4 to 5 per cent this year, traditional media continue to lose share. In the UK, for example, print media advertising shrank 5 per cent last year, while online grew by almost two-thirds. Share prices of Internet stocks will continue to fluctuate greatly, but it is traditional print media companies that face the toughest future.